HCI Bibliography Home | HCI Conferences | HFS Archive | Detailed Records | RefWorks | EndNote | Hide Abstracts
HFS Tables of Contents: 87-187-288-188-289-189-290-190-291-191-292-192-293-193-294-194-295-195-2

Proceedings of the Human Factors Society 32nd Annual Meeting 1988-10-24

  1. HFS 1988-10-24 Volume 2
    1. Organizational Design and Management: Panel
    2. Organizational Design and Management: Participatory Ergonomics: Organizational Strategies and Development
    3. Organizational Design and Management: Panel
    4. Organizational Design and Management: Managing Shiftwork
    5. Organizational Design and Management: Macroergonomics Applied to Organizational Design and Quality of Work Life
    6. Organizational Design and Management: Macroergonomics: Methodologies and Management Implications
    7. Personality and Individual Differences in Human Performance: Personality, Individual Differences, and Human Performance
    8. Personality and Individual Differences in Human Performance: Individual Differences Implications for the "New Look" in Human Factors Microcomputer-Based Performance Testing
    9. Personality and Individual Differences in Human Performance: Gender, Intelligence, and Human Performance
    10. Personality and Individual Differences in Human Performance: Methods and Applications of Mental Models of Complex Performance
    11. Safety: Accident Analysis
    12. Safety: Product Safety Warnings and Devices
    13. Safety: Transportation Safety
    14. Safety: The Arnold Small Lecture in Safety
    15. Safety: Robotics/Industrial Safety
    16. Safety: Driver Behavior
    17. Safety: Workplace Safety: Physical Activity and Other Tasks
    18. System Development: Individual Differences Make a Difference in Systems Research
    19. System Development: Defining the Human-Computer Interface
    20. System Development: Tools for the Practitioner
    21. System Development: Tools, Testbeds, and Prototypes
    22. System Development: Human Factors in Navy Systems
    23. System Development: System Development Applications
    24. Test and Evaluation: Workload Evaluation: Technique and Application
    25. Test and Evaluation: Test and Evaluation in Operational Settings
    26. Test and Evaluation: Panel
    27. Test and Evaluation: Innovative Approaches to Human Factors in Operational Test and Evaluation
    28. Test and Evaluation: New Methodology for Test and Evaluation
    29. Training: Military Training Data Bases
    30. Training: Performance Assessment Techniques and Applications
    31. Training: Approaches to Skill Acquisition
    32. Training: Training System Design -- Techniques and Issues
    33. Training: Transfer of Training Paradigms and Learning Theory
    34. Training: Training Potpourri
    35. Training: Making Computer Conferencing Work for Army Training: From Lessons Learned to Testbed Development
    36. Visual Performance: Visual Search and Detection
    37. Visual Performance: Visual Display Design: Theory and Practice
    38. Visual Performance: Panel
    39. Visual Performance: Information Portrayal Determinants of Complex Decision Making
    40. Visual Performance: Computer Displays
    41. Visual Performance: Physiological and Subjective Assessment of Workload
    42. Visual Performance: Advanced Displays I
    43. Visual Performance: Advanced Displays II
    44. Visual Performance: Time-Sharing, Vigilance, and Behavioral Assessment of Workload

HFS 1988-10-24 Volume 2

Organizational Design and Management: Panel

The Application of Sociotechnical Systems Design to Computer Integrated Manufacturing BIBA 749-750
  Ann Majchrzak; John Cotter; Robert Karasek; James Taylor; Leslie Eveland
Sociotechnical Systems (STS) theory rests on two premises. The first is that, in any purposeful organization in which humans are required to perform activities, the desired output is achieved through the actions of a social as well as a technical system. These systems are interlocked such that the achievement of the output becomes a function of their joint operation. The second premise is that every sociotechnical system is embedded in an environment that is influenced by a culture, its values, and a set of generally acceptable practices. Thus, any organization operates as an open system, in which the boundaries between the environment and the individual systems are highly permeable (see Davis and Taylor, Design of Jobs, 1979 for a fuller discussion of the basic tenets of STS theory.)

Organizational Design and Management: Participatory Ergonomics: Organizational Strategies and Development

Critical Linkages: Top Management's Role in Making Technology Work BIBA 751-754
  Susan M. Dray
It is clear that it is critical to have technical systems which are "linked to business strategy", but exactly how to do this remains largely undocumented. This paper presents a case study of how the Senior Management Technology Steering Committee at IDS Financial Services has begun to forge this link.
Participatory Ergonomics: Current Approaches to Improving Organizational Effectiveness and Quality of Work Life BIBA 755
  Ogden, Jr. Brown
Participatory ergonomics is an idea whose time has come there are many approaches which have been utilized by organizations to improve productivity and enhance quality of work life. Participation itself is not a new idea, but because of current organizational and environmental forces for change, new organizational philosophies are emerging which are developed, designed and operated with participation of the employees concerned and which do result in improved organizational effectiveness and quality of work life.
Xerox Leadership Through Quality: Merging Human Factors and Safety Through Employee Participation BIBA 756-759
  Howard B. Lewis; Andrew S. Imada; Michelle M. Robertson
Organizations are addressing problems resulting from increasing international competition and complex technologies by implementing participative management techniques. Recent evidence suggests that participatory ergonomics can be an effective, cost-efficient method for solving a variety of production, human factors, and safety related problems. This paper presents an example of how participative management has been used effectively in introducing human factors, sociotechnical, and safety change in a large international organization. Case studies such as this one demonstrate how participation can reduce costs, training requirements, injuries and absenteeism.
The Evolving Role of Task-Group Leaders: A Field Study BIBA 760-764
  Robert F. Randolph
Leaders of task-oriented production groups play an important role in their group's functioning and performance. That role also evolves as groups mature and learn to work together more smoothly. The present study uses a functional analysis of the evolving role of supervisors of underground coal mining crews to evaluate the impact of supervisors' characteristics and behaviors on their crews' efficiency and safety, and makes recommendations for improving supervisory selection and training. Data were gathered from a sample of 138 supervisors at 13 underground coal mines. Detailed structured observations of the supervisors indicated that most of their time was spent attending to hardware and paperwork, while comparatively little time was spent on person to person "leadership." The findings point out that while group needs changed over time, the supervisors' behaviors typically did not keep pace and probably restricted group performance.

Organizational Design and Management: Panel

Putting It in Perspective: Different Disciplines' Approaches to Managing Technologically-Stimulated Change BIBA 765
  Susan Dray; David Hopelain; Andrew Imada; Rob Kling; Betty Mallott; Michelle Robertson; James Taylor
Sociotechnical systems (STS), Macroergonomics, Behavioral Science, Participatory Ergonomics, Computer Science, Organizational Development (OD), Sociotechnical systems (STS). These are several of the disciplines which are participating in today's business and information systems environment to manage the organizational changes that the design and implementation of new technology brings with it. Five years ago, the major issue was "How do we get managers to be aware that technology brings with it organizational changes which need to be proactively planned for and managed?" But today, as more and more managers are aware of this, the major issue has shifted to "How do we actually plan and manage these changes?"
   The purpose of this panel is to discuss how different disciplines answer this question. The panelists each represent a different approach and will discuss briefly the philosophical roots of their discipline, and then discuss more fully the typical approaches and tools which they would use to help managers address these issues. We will then discuss differences and similarities, drawing from the audience's experiences where possible, in an attempt to understand ways we can learn from each other.

Organizational Design and Management: Managing Shiftwork

Managing Shiftwork BIBA 766
  Jon A. Wagner
As our culture increasingly depends on round-the-clock operations to provide necessary services and efficiently utilize productive capacities, more and more people are required to work shiftwork. Shiftwork, as experienced in this country, normally includes work during hours of darkness and work on weekends. Often, this round-the-clock coverage requires workers to "rotate" through three shifts (day, afternoon, and night), or to work a steady run of afternoon or night shifts. Previous research has linked shiftwork with disruptions of family life, health, sleep, safety and productivity, in a variety of work situations. In addition, a poorly designed work schedule can adversely affect job satisfaction, employee turnover, and absenteeism. Given these facts, managers need to be made more aware of these often hidden challenges facing them and their workers. The way to meet these challenges is with research, education, and implementation of improved methods of scheduling and handling the management of shift workers. Such experimental improvements have already paid benefits both on and off the job for workers in some continuous operations.
Technical Comparison of 8-vs-12 Hour Shift Schedules: A Case Study BIBA 767-771
  Marty Klein
An analysis of the social, biological, fiscal, and operational, characteristics of a 12-hour shift schedule, as compared to an 8-hour shift schedule, was conducted for two employee groups in the power industry. The 12-hour shifts appeared to have social advantages; the biological effects were questionable at best; and the fiscal and operational consequences were clearly disadvantageous.
Quality of Life for Shift Workers and Their Families BIBA 772-774
  Janie O'Connor
Non-traditional working hours are a "way of life" for those people who work a shift rotation. Laborers who work day, afternoon, and night shifts in a three week period often complain of digestive problems, a feeling of disorientation and problems with family and social relationships. Their families reported a lack of effective communication and limited involvement in traditional family celebrations/events. This paper describes the educational program which resulted from the cooperative efforts of the Minnesota Extension Service, industry, and shift workers' families. The program helped to provide some alternatives for families as they attempted to manage this stressful lifestyle.
Shiftwork Solutions: A Systems Perspective BIBA 775-776
  Susan L. Koen
This paper presents both a process and a starting point for resolving the many complex problems associated with shiftwork. The author argues that an organizational development (OD) framework is required to diagnose shiftwork consequences and design effective interventions. Moreover, the paper reveals that the appropriate starting point for a shiftwork OD intervention is management education aimed toward the establishment of an organizational culture which values "off-shift" personnel.

Organizational Design and Management: Macroergonomics Applied to Organizational Design and Quality of Work Life

Job Stress, Job Satisfaction, and Work-Related Illness in Offices BIBA 777-779
  Alan Hedge
A questionnaire survey of demographic, environmental, psychological, and occupational influences on health was conducted in 6 office buildings in the UK. A total of 486 completed questionnaires were analyzed (85% response rate). The results showed that the prevalence of symptoms was not associated with job satisfaction, and the previously reported sex difference in symptom prevalence was not confirmed although this approached significance. The results suggest that work-related illness is strongly associated with self-reported job stress and negative perceptions of the office environment, i.e., dissatisfaction with temperature, ventilation, lighting and noise.
A Macroergonomic Approach to Designing a University College BIBA 780-784
  Hal W. Hendrick
The sociotechnical system components of the University of Denver's newly formed college of Systems Science were assessed using a macroergonomic approach to determine their implications for the College's organizational design. The resulting analysis led to the structuring of the College's organizational complexity including integrating mechanisms, degree of centralization, and formalization. These, in turn, have guided much of the design of specific jobs and human-machine interfaces. The macroergonomic assessment and resulting organizational design are described.
Office Environment Index '88: A Poll of Workers, Executives, and Facility Managers on Life and Work in Today's Offices BIBA 785-789
  Paul Cornell
With the advent of the information age, increasing numbers of workers are now engaged in office work. There is much to learn about this new majority in the workforce, but few vehicles for gathering information. The Office Environment Index (OEI) is an on-going effort to address this informational need. Conducted by Lou Harris and Associates with the collaboration of Steelcase and several professional organizations, the OEI surveys office workers, their management, and others concerning issues which impact quality of work life and effectiveness. This latest survey included 1031 office workers, 150 facility managers, 150 executives, and 150 interior designers. The focus of this analysis is on job satisfaction and perceived productivity and the variables which influence them. In particular, the role of job characteristics, the environment, and computer usage were examined. The results indicate that people who judge themselves good performers tend also to be satisfied. However, not all those who judge themselves satisfied also judge themselves good performers. The variables examined tended to impact satisfaction more than productivity. Thus, it is felt that they impact performance indirectly via their role in satisfaction.

Organizational Design and Management: Macroergonomics: Methodologies and Management Implications

Solution Bias in Complex Systems Modeling BIBA 790-793
  Bruce Kaplan; Mike Mecherikoff; Harold Blackman
Each discipline tends to use analytic tools that lead them to solutions within their own discipline, and steer them away from others. Within a discipline, we tend to pose solutions that align with our areas of interest or expertise. Clients can be guided into work which may not be the best solution to their particular set of problems or needs.
Identifying and Weighting Factors Effecting Work in a Mechanized Office Environment BIBA 794-797
  Henry E. Bender; Vincent Conte; Richard Bannecker
Decision making concerning the allocation of and distribution of funds in highly automated or computerized offices is often biased by the orientation of the decision maker, and the previous cost benefit analysis of the "system" implementation study. In such an environment, costs are often allocated to hardware or software enhancements, without regard to other factors potentially influencing working productivity or efficiency.
   The present study addressed the problem of developing a methodology that would allow for the most expansive listing of factors influencing worker productivity or efficiency. The method used allowed for the greatest amount of input from subject matter experts as well as from system users.
   The data gathering method is described that facilitated the development of a questionnaire method implemented in a work environment of a major inventory and control system office. The data analysis indicates the functionality of the method, and its usability in a vast number of environments.
A Strategy for Managing the Organizational Impact of Computers in Small Businesses BIBA 798-802
  Lane Davis-Coury; Bruce G. Coury
Human Factors can play an important role in the implementation of computer systems in small companies. The degree of effectiveness is dependent upon a thorough understanding of the unique characteristics of that group of users. This paper discusses the special problems associated with small companies and presents a strategy for effectively introducing new technology.
The Matrix Organization: Can the Human Factors Specialist Thrive or Merely Survive? BIBA 803-806
  Charles Bowen
An increasing amount of Human Factors (HF) specialists are providing their services through matrix organizations. If the Human Factors Specialist is to be successful, an understanding of recent organizational research involving matrix organizations is important. This paper differentiates among three basic types of organizations: the Functional organization, the Product organization, and the Matrix organization and examines the organizational pressures that force organizations to turn to a matrix organization. The advantages and disadvantages are explored. As the matrix structure grows in popularity, Human Factors Specialists familiar with the principles of a matrix organization, will be better equipped to deliver their services in the most effective manner.

Personality and Individual Differences in Human Performance: Personality, Individual Differences, and Human Performance

Validation of a Computer-Based Aviation Secondary Selection System for Student Naval Aviators BIBA 807-811
  G. D. Gibb; D. L. Dolgin
This report describes the validation of an automated aircrew selection battery that measures cognitive processes, psychomotor skills, and time-sharing abilities. Results indicate that performance-based test measures can be used to predict flight training performance.
Evaluation of an Automated Series of Single and Multiple-Psychomotor and Dichotic Listening Tasks BIBA 812-816
  Glenn R. Griffin
A series of automated psychomotor and dichotic listening tasks, which require little administrative support and provide automatic scoring of performance, has been developed. The automated tasks account for additional variance in predicting Navy flight training performance beyond that of current selection tests.
Current Developments in Research on Air Force Pilot Characteristics BIBA 817-821
  Frederick M. Siem
A personality inventory was given to 509 USAF pilot candidates. The items were combined into five measures, two of which differentiated training successes from failures; graduates demonstrated higher self-confidence and less dogmatism. As an alternative approach to examining simple relationships between personality characteristics and training outcomes, personality profiles were examined as predictors of performance criteria. The value of this approach was demonstrated by better discrimination of training graduates from non-graduates. The implication of these results are discussed, as are plans for other research projects designed to replicate and extend the findings from the current study.
The Effect of Goals and Type A-B Behavior on Changes in Bias and Sensitivity BIBA 822-825
  Robert E. Lewis
The effects of a situational and an individual differences variable on changes in bias and sensitivity during a proofreading task are examined. Externally set goals provided situational parameters while the Type A-B behavior pattern provided a measure of individual differences. Subjects responded to goals of increasing difficulty by increasing their performance as measured by the amount of text proofread and by decreasing their sensitivity. Thus, subjects attempted to meet a situational demand to produce more by increasing the quantity of their output at the expense of quality.
Human-Computer Interaction: Analyses of Individual Differences and Decision-Making BIBA 826-830
  Anita Kak Ambardar
The primary purpose of the present program of research is to answer the following questions:
  • 1. Do fundamental cognitive individual differences interact with specific human
        / computer interface features?
  • 2. What cognitive dimension, beyond experience, are really important to
        human/computer interaction?
  • 3. Aside from the classification of users into "expert" and "novice"
        categories, is a given interface design equally good in supporting the
        problem solving activity of any particular person? The main goal of this research is to establish the extent to which more global, enduring and basic cognitive characteristics of the target users must be considered in the design of human/computer interfaces. Specifically, the hypothesis being tested is that individual differences in various dimensions interact with features of human/computer interfaces. Furthermore, by taking these interactions into account, such interfaces can be optimized to user populations of differing cognitive styles.
  • Personality and Individual Differences in Human Performance: Individual Differences Implications for the "New Look" in Human Factors Microcomputer-Based Performance Testing

    Using Robust Statistics and Distribution Parameters to Establish Valid Individual Differences in Computer-Based Cognitive Testing BIBA 831-835
      Benjamin A., Jr. Fairbank
    Data gathered in large-scale computer-based cognitive laboratories occasionally appear less orderly than data gathered on similar tasks in laboratories where close interaction between subject and experimenter is possible. The present research addressed the question of whether the use of robust statistics could make such data appear more orderly and lawful. Of related interest was the question of whether parameters which describe whole distributions of data, rather than only means and standard deviations, could be used to establish reliable and valid individual differences. For the large sample sizes used here the robust estimators did not outperform standard statistics. The distribution parameters were not sufficiently reliable to be useful in characterizing psychological processes.
    Slope-Controlled Performance Testing BIBA 836-837
      Marshall B. Jones
    Cognitive-ability tests, though promising in other respects, generally show pronounced practice effects and have weak test-retest reliabilities. One reason for the low reliabilities appears to be that practice effects themselves vary from individual to individual, so that subjects differ not only in the levels at which they are performing when testing ends but also in the slopes leading up to those levels. Since slope of the performance curve late in practice has been shown to affect performance at reacquisition (retest), uncontrolled variation in slope may lower test-retest reliability. A possible approach to this problem is experimentally to control slope during testing so that all subjects are improving at roughly the same rates when testing ends. The expected effect is that, with inter-subject differences in slope controlled, the temporal stability of cognitive-ability tests will improve. If temporal stability improves, however, predictive validities ought also to improve.
    A Differential Approach to Microcomputer Test Battery Development and Implementation BIBA 838-842
      R. S. Kennedy; D. R. Baltzley; M. K. Osteen; J. J. Turange
    The Automated Performance Test System (APTS), a microcomputer-based performance test battery, has been under development for over five years. The emphasis has been on psychometric theory and utility for repeated-measures applications during extended exposure to various environmental stressors. Stability of means and variances and retest reliability have been the criteria for suitability of a test. In addition, differential stability (i.e., parallelism of individual differences over sessions) is a unique requirement for test acceptability in this battery. In the present menu of "qualified" mental tests, there are presently more than 30 fully up-and-running on portable Zenith and NEC microcomputers as well as floppy disks for IBM compatible systems. Qualified tests stabilize in less than 10 minutes and possess test-retest reliabilities of r > 0.70 for a three-minute test/work period. The battery includes tests of cognition, information processing, psychomotor skill, memory, mood, and others. More than a dozen normative laboratory and field studies have been conducted to validate the stability and reliability requirements of the tests in the battery and more than a dozen "sensitivity" studies have been or are in the process of being completed. To date, one or more tests have been shown sensitive to chemoradiotherapy, sleep loss, hypoxia, amphetamine, hyoscine, mood disorders, thermal stress, sensory deprivation, motion stress, altitude, fatigue, and alcohol use. The present paper describes our experiences with these tests and reports on a recommended menu for a short battery (6 minutes), a middle length battery (12 minutes), and a longer battery (22 minutes). Other test batteries which are presently under development do not pay as much attention to individual differences. The consequence of this inattention is low sensitivity if test-rest reliability is poor and inability to properly attribute effects if instability occurs.
    Factors in Predicting Success in the Acquisition of Cognitive Skill BIBA 843-847
      Patrick C. Kyllonen
    This paper reviews two studies that have examined the relationship between performance on basic cognitive tasks, administered on microcomputers, and performance on two learning tasks. One learning task involved computer programming, the other involved learning to trace signals through logic gates, a component of electronics troubleshooting skill. From previous research we have established a four-source framework: we assume that observed learner differences are due to differences in processing speed; processing capacity; and the breadth, extent and accessibility of conceptual knowledge and procedural and strategic skills. In both studies, we attempted to predict the proficiency (i.e., speed and accuracy) with which individuals were able to acquire skill in the domain area (programming, troubleshooting) as a function of their scores on the four cognitive factors. Each cognitive factor was indicated by performance on two computerized tests. Skill acquisition proficiency on the learning tasks was decomposed into separate scores for (a) speed acquisition of the initial declarative foundations of the skill (the facts), (b) speed of acquisition of the ability to apply the factual knowledge to solve domain problems (the skill itself). In both studies, working memory capacity was the best predictor of both the speed with which domain facts were learned, and of one's ability to translate those facts into rules that could be employed in problem solving.

    Personality and Individual Differences in Human Performance: Gender, Intelligence, and Human Performance

    Gender Differences in Criterion Task Set Performance and Subjective Ratings BIBA 848-852
      Betina Schlegel; Robert E. Schlegel; Kirby Gilliland
    This paper summarizes gender differences in performing various elements of the Criterion Task Set. Performance data and Subjective Workload Assessment Technique ratings were analyzed for 28 men and 28 women who participated in a large-scale CTS validation study. In general, women tended to perform slightly better than men on the majority of tasks. In particular, performance by women was better on Grammatical Reasoning, Linguistic Processing, Mathematical Processing, and Memory Search. Response times on Probability Monitoring were faster for women but at the expense of a greater number of False Alarms. Men performed better only on the high level of Continuous Recall and the medium level of Unstable tracking. Women tended to give lower subjective ratings than men to those tasks with a high memory component and gave higher ratings than men to those tasks involving input/output spatial elements.
    Gender Differences in the Strain Response to Job Demand BIBA 853-856
      Paul R. McCright
    In a study of the effects of variations in the levels of job demand on self-reported levels of job-related strain, an unanticipated gender differential was found. Higher levels of job demand were hypothesized to lead to higher levels of job-related strain. No differential effect due to gender was anticipated. Subjects in the high demand condition reported significantly more job-related strain than did subjects in the low demand condition. However, when an analysis of covariance was performed, gender showed an unexpected interaction effect with demand. Females experienced lower levels of strain in the low demand condition than did males. In the high demand condition, females experienced higher levels of strain than did males. This indicates that women were more sensitive to demand variations than men. This gender difference suggests that assignment of workers to certain positions based on gender may reduce overall levels of job-related strain.
    Estimation of Duration and Mental Workload at Differing Times of Day by Males and Females BIBA 857-861
      P. A. Hancock; G. J. Rodenburg; W. D. Mathews; M. Vercruyssen
    Two experiments are reported which investigated whether male and female operator duration estimation and subjective workload followed conventional circadian fluctuation. In the first experiment, twenty-four subjects performed a filled time-estimation task in a constant blacked-out, noise-reduced environment at 0800, 1200, 1600 and 2000h. In the second experiment, twelve subjects performed an unfilled time estimation task in similar conditions at 0900, 1400, and 1900h. At the termination of all experimental sessions, participants completed the NASA TLX workload assessment questionnaire as a measure of perceived mental workload. Results indicated that while physiological response followed an expected pattern, estimations of duration and subjective perception of workload showed no significant effects for time-of-day. In each of the experiments, however, there were significant differences in duration estimates and mental workload response depending upon the gender of the participant. Results are taken to support the assertion that subjective workload is responsive largely to task-related factors and indicates the important differences that may be expected due to operator gender.
    A Gender Profile: U.S. General Aviation Pilot-Error Accidents 1982-1985 BIBA 862-866
      Gayle J. Vail
    Women in aviation are having an impact on pilot safety records -- a beneficial one. Evidence has shown that they are the safer of the genders while flying as Pilot-In-Command in General Aviation Flying.
       Data was analyzed from the NTSB files for the year 1982-1985. The results found a positive gender factor for females in number, type, and cause of pilot-error related accidents.
    Individual Differences in Visual Perceptual Processing: Attention, Intelligence, and Display Characteristics BIBA 867-871
      Lila F. Laux; David M. Lane
    Researchers have found little evidence that the ability to identify briefly presented simple stimuli (single letter, symbols) is related to intelligence in normal populations although performance on visual processing tasks which impose a greater attentional load (words, phrases, sentences) has been found to correlate with scores on reading tests. This study assessed the correlation between performance on seven visual processing tasks and intelligence as measured by the Raven's and the Nelson-Denny Reading Test. Intelligence correlated with tasks that required the identification of a confusable target, tasks in which the target was defined by a conjunction of features, and tasks in which the target was defined by its location. Intelligence did not correlate with the ability to identify single targets or targets defined by a single non-confusable feature. Other studies have shown that when attentional load is increased by increasing the number of characters in the display, performance is affected differently for confusable and conjunction targets. Increasing the attentional load reduces the number of hits in the confusable condition and increases the number of false alarms in the conjunction condition. In this study these two measures correlated with intelligence but not with each other, meaning that they assess different aspects of visual perceptual processing efficiency. We conclude that when it is critical to correctly identify targets and to avoid false alarms when monitoring complex displays, targets should not be confusable and should be defined by a single feature. When this is not possible, it is important to select operators who are more efficient at processing confusable and conjunction-defined stimuli.

    Personality and Individual Differences in Human Performance: Methods and Applications of Mental Models of Complex Performance

    Overview: The Use of Think Aloud Verbal Protocols for the Identification of Mental Models BIBA 872-874
      Harold S. Blackman
    Results regarding the use of protocol analysis techniques are presented to show how they may improve the models identified through other knowledge engineering techniques and how these models may then be used to improve performance through training. Data from two experiments are presented and discussed.
    Model for Measuring Complex Performance in an Aviation Environment BIBA 875-878
      Heidi Ann Hahn
    An experiment was conducted to identify models of pilot performance through the attainment and analysis of concurrent verbal protocols. Sixteen models were identified. Novice and expert pilots differed with respect to the models they used. Models were correlated to performance, particularly in the case of expert subjects. Models were not correlated to performance shaping factors (i.e., workload).
    Functional Models of Complex Human Performance: Application to the Assessment of Pilot Performance BIBA 879-882
      William R. Nelson
    A method has been developed for formulating integrated models of complex human and machine performance. The functional models can be used to model human tasks, measure human performance, identify problem solving strategies, estimate human error probabilities, define training requirements, investigate accidents, and design decision aids for complex cognitive tasks. This paper summarizes the application of the functional modeling technique to the collection and analysis of data from an experiment designed to assess pilot performance while responding to malfunctions.
    Where To from Here? Future Applications of Mental Models of Complex Performance BIBA 883-884
      Heidi Ann Hahn; William R. Nelson; Harold S. Blackman
    The purpose of this paper is to raise issues for discussion regarding the applications of mental models in the study of complex performance. Applications for training, expert systems and decision aids, job selection, workstation design, and other complex environments are considered.

    Safety: Accident Analysis

    A Computer-Based Safety Assessment for Flight Evacuation: SAFE BIBA 885-888
      Robert J. Shively
    Recently, the U.S. emergency medical services (EMS) industry has received a great deal of negative publicity concerning its safety record. It has been noted that the EMS industry has an accident rate that is five times that of the rest of the helicopter industry (Harvey and Jensen, 1987; Harvey, 1986). While it is true that during 1987 and early 1988 the safety record has improved, the industry cannot become complacent. The National Transportation and Safety Board recently conducted a study of the EMS industry and returned specific recommendations for the FAA and NASA. One of the critical factors in EMS missions is the pilot's decision to accept or reject a mission. This can often be influenced by such factors as the urgency of the care required. This, along with other factors, may prompt a pilot to accept a mission of unacceptable risk. The present paper presents a computer-based decision aid, based upon earlier work by the Army and Coast Guard, to assist the pilot in objective assessment of the probable risk of an EMS mission. Data for validation of this technique will be collected at an EMS operator and from the EMS Safety Reporting Service.
    Army Materiel Handling Accident Analysis BIBA 889-891
      Allen E. McMichael; Dave Durbin; Gerald L. Gamache
    Successful Army operations depend on the efficient handling, storage, and flow of materials. Accidents associated with materiel handling activities not only affect the efficiency of an operation but also endanger the lives of Army personnel. In addition, the annual cost to the Army for materiel handling accidents averages approximately $4,315,836. The high incidence and cost of materiel handling accidents poses significant operational problems for the army. The Army could make great strides in alleviating these operational burdens as well as meeting its safety goals through concerted accident prevention efforts. The U.S. Army Safety Center is making its first attempt to quantify the system problems in the materiel Handling Major Problem Areas. Improvements in the design of materiel handling equipment and in supervisory practices and training methods may be applicable both to other government agencies and in the private sector.
    A Relative Analysis of Downhill and Cross-Country Ski Injuries BIBA 892-896
      Jasper E. Shealy; David A. Miller
    This is a clinical analysis of XC and DH injuries reported thru the CPSC NEISS data files. It suggests that there are significant differences between the two sports an that there are occasionally significant interactions with gender was well. There are some implications with regard to injury mechanisms as well as hardware factors. In order to more fully understand and interpret these findings, it will be necessary to couple these findings with an examination of the populations at risk in a quasi-epidemiological methodology.

    Safety: Product Safety Warnings and Devices

    Effectiveness of Product Safety Warnings Over Time, and the Generalization of Warning Signs BIBA 897-900
      Madeleine Orr; Stanley T. Hughes
    The extent to which consumer's attention for safety signs varies over time and the extent to which consumer's impression of product safety are altered by the presence of a safety sign were investigated. A total of 60 subjects had one of two types of signs (safety message or security message) placed on the front of a VDU. Subjects were administered a questionnaire after either one or three weeks of exposure to the signs. Results indicate that safety signs can be rapidly habituated to if the sign's content is not seen as relevant to the task at hand. In addition it was found that the presence of a safety sign resulted in subjects identifying more product related safety hazards.
    Warning Compliance: Behavioral Effects of Cost and Consensus BIBA 901-904
      Michael S. Wogalter; Nancy A. McKenna; Scott T. Allison
    Two laboratory experiments were conducted to examine the behavioral effects of cost and consensus on warning compliance. Subjects performed a chemistry demonstration task using a set of instructions that contained a warning directing them to wear a safety mask and gloves. In Experiment 1, cost was manipulated by locating the masks and gloves in either an accessible location (low cost) or a less accessible location (high cost). In Experiment 2, consensus was manipulated by the additional presence of a confederate subject who either did or did not comply with the warning. The results showed reduced compliance to the warning when the cost was high, and that the compliance rate was biased up or down depending on the behavior of the confederate. Implications of this research for facilitating warning effectiveness and safety are discussed.
    Memory of Instruction Manual Warnings: Effects of Pictorial Icons and Conspicuous Print BIBA 905-909
      Stephen L. Young; Michael S. Wogalter
    The present research sought to determine whether the salience of warning messages would improve the memory of warnings in proceduralized instructions. Subjects studied one of four instruction manuals for a gas-powered electric generator under the guise that they would later operate the generator. In the manual, the appearance of eight different warning messages were altered in two ways: 1) The verbal messages were printed in either conspicuous print (larger with color highlighting) or in plain print (same as the other text). 2) The verbal warning messages were either accompanied by meaningfully-related icons or the icons were absent. Three kinds of memory tests were given to subjects. The results showed that subjects who received the manual containing Conspicuous Print, Icons Present warnings recalled the verbal warning content and the semantic learning of the icons significantly better than subjects who received one of the three manuals. Implications for the design of instruction manual warnings are discussed.
    Improving Swimming Pool Warning Signs BIBA 910-914
      Beth A. Loring; Michael E. Wiklund
    The U.S. Consumer Product Safety commission sponsored us to perform a human factors evaluation of existing swimming pool warning signs. Our study covered warnings which convey the messages "NO DIVING" and "WATCH CHILDREN". These warnings are particularly intended to reduce the incidence of diving accidents involving teenage boys and drowning accidents involving children under five; population groups that are over-represented in accident statistics. Our evaluation of twenty-two existing signs uncovered deviations from warning sign design principles and identified opportunities to improve each of the signs. Following the evaluation, we developed improved signs and tested them using teenage boys and mothers of young children as subjects. We then made final recommendations to the CPSC for improved signs.
    Effectiveness of Protective Devices to Prevent Child Drownings in Home Swimming Pools BIBA 915-918
      Neil D. Lerner; Catherine A. Sedney; Janis Cannon-Bowers
    Drowning in home swimming pools is one of the leading causes of accidental death for children under age five. This paper considers the effectiveness of protective devices, such as fencing, for the prevention of residential pool child drownings. Empirical studies of barrier effectiveness are limited and methodologically flawed. Current codes and standards suffer serious inadequacies. The typical child drowning scenario is discussed, and an approach to a safety system providing layers of protection is described.

    Safety: Transportation Safety

    Patrol Car Reduces Driver Reaction Times BIBA 919-922
      Heikki Summala; Jarkko Hietamaki; Antero Lehikoinen; Jukka Vierimaa
    This research showed that when having passed a patrol car on the road side, drivers' responses to a cyclist coming from a side road occur at a shorter latency. When stopped and interviewed afterwards, the drivers were not able to veridically estimate the time available for their response.
    Risktaking and Driver Behaviors: A Laboratory Study BIBA 923-927
      Carol F. Shoptaugh
    A number of variables have been implicated as predictors of actual risky driving behaviors. However, due to differing methodologies, the literature shows few consistent findings. The current study is an attempt to establish a more complete understanding of the relationship between risk related characteristics and actual risk taking decisions. It was predicted that individuals who had a greater propensity for taking risks would also be more prone to making risky decisions in a simulated driving task.
       Sixty subjects (30 male, 30 female) were selected based on their Kogan and Wallach Choice Dilemma risktaking scores (15 high and 15 low risk takers in each gender group). Subjects participated in two 1 1/2 hour experimental sessions. Session one was a video tape risk choice session and session two, a battery of demographic, driving and risktaking characteristic questionnaires were given.
       The most significant finding in this study involved the misuse of speed and distance in making turn decisions. All subjects adopted a safer criterion than the normative model for left turn gap distances, but for right turn merging gaps high risktaking subjects perceived significantly more gaps as safe than did low risktaking subjects. Further, as speed increased from 30mph to 55mph all subjects believed more gaps to be safe for right turn merging. This miscalculation could result in a rear end accident.
       Most demographic, driver and risktaking measures failed to correlate significantly with risky decision making. Only the Choice Dilemma and the Pelz-Schuman Impulsivity questionnaire correlated with each other and the risky driver decisions.
    Determining Perceived Traffic Sign Dimensions with Multidimensional Scaling BIBA 928-932
      Cary Robb Jensen; Loy A. Anderson; Joe, Jr. Mullen
    The evaluation of current and potential traffic signs is necessary in order to ensure that the signs are effective. Laboratory studies are an important first step in evaluating current and potential traffic signs in order to minimize the risk and expense associated with field research. This paper describes the application of multidimensional scaling to traffic signs, a method that appears to be well suited for determining perceived traffic sign dimensions. In two studies subjects judged the similarity of all possible pairs of 16 traffic signs. Three interpretable dimensions were found. These dimensions, in order of extraction, were color/content, message form (pictorial vs. verbal), and shape. The validity of this research technique and the limitations of these research results are discussed.
    Prevention of Accidents at Road-Rail Level Crossings Protected with Automatic Barriers BIBA 933-937
      Shigeru Haga
    A recent study on level crossing safety is reported. The study employed three different approaches: a survey of drivers' attitude to the level crossing, quantitative estimation of accident risk from characteristics of level crossings, and improvement of crossing design from the human factors point of view. The results have been utilized by railway companies and police authorities in safety campaigns, driver education, safety investment, and improvement of warning systems for level crossings.
    Safety Perceptions and Information Sources for ATVs BIBA 938-942
      Edward W. Karnes; S. David Leonard; Herbert C. Newbold
    Safety issues concerning all-terrain vehicles (ATVs) have become important for human factors professionals, because of the need to reduce the accidents and injuries associated with their use. Human factors experts have also been called upon to testify in legal suits occasioned by some accidents. This paper discusses some of the problems associated with the safety of ATVs and presents data concerning riders and observes ability to estimate their speed. Speed estimates are lower than actual speeds at low speeds and higher than actual speeds at high speeds. It is concluded that information about the speed capabilities of ATVs is important consumer information and should be made conspicuous in advertising and other informational channels about ATVs.

    Safety: The Arnold Small Lecture in Safety

    Development of Subjective Data for Performance Prediction BIBA 943-947
      David Meister
    The point is made that in the absence of other human performance data sources, the use of subjective estimates is justifiable and, even more, necessary. The most common methods of eliciting these estimates are described.

    Safety: Robotics/Industrial Safety

    Perception of Safety Zone Around an Industrial Robot BIBA 948-952
      Waldemar Karwowski; Mansour Rahimi; David L. Nash; Hamid R. Parsaei
    Laboratory experiments were performed to investigate human perception of safe zone around an industrial robot. It was shown that an angle of approach toward the robot, speed of robot motions and exposure to a simulated accident significantly affected the student subject's perception of the safe area around the MH33 robot. On the average, across all approach angles, the subjects selected distances of 49.2 and 70.0 cm from the robot's working envelope, for the accident and non-accident group, respectively.
    A Robot Safety Experiment Varying Robot Speed and Contrast with Human Decision Cost BIBA 953
      John Etherton; John E. Sneckenberger
    An industrial robot safety experiment was performed to find out how quickly subjects could respond to unexpected robot motion at selected slow robot speeds and how frequently they did not respond when a signal (an unexpected motion) should have been detected. The dependent variable in the experiment was the overrun distance beyond an expected stopping point that a robot arm traveled before a person actuated a pushbutton to stop the robot. A robotics technician risks being fatally crushed if a robot should trap the person against a fixed object. This risk can be reduced if, during programming and troubleshooting tasks, the robot is moving at a slow speed which gives the worker sufficient time to actuate an emergency stop device before the robot can reach the person. A General Electric P-50 robot was programmed to provide the experimental situation. Nine subjects were tested, all in the age range 20-30. The subjects were male volunteers, not currently working in a job involving robot programming or maintenance.
    A Study of Expert Judgment on Human Error Probability BIBA 954-957
      Bernhard Zimolong; Barbara Stolte
    An experiment was conducted to derive empirically human error probabilities from a task performed under 12 different conditions. The task was to control a simulated flexible manufacturing scenario (FMS) under three Performance Shaping Factors (PSF): Incentive, workload and event frequency of breakdowns. Six experts with backgrounds in human factors assess the relative contribution of each PSF in affecting the likelihood of failure with the multi attribute decomposition technique. The conversion of the assessment values to probabilities was achieved by the use of an empirically derived calibration equation. Results indicate a poor match of empirical HEPs and their estimates and increase the doubts that subjective estimation is a solution to the missing data problem in reliability measurement.
    Human Factors Model of Workplace Accident Causation BIBA 958-962
      David M. DeJoy
    This paper proposes a human factors model of workplace accident causation. Particular attention is given to merging traditional human factors considerations with those related to self-protective behavior. The model focuses on human error, and three categories of diagnostic factors are proposed for analyzing the determinants of error. The diagnostic factors include: person-machine communication, environment, and decision-making. These factors are then linked to three general types of interventions: those involving system modification, organizational modification, and self-protection.

    Safety: Driver Behavior

    The Effects of Rumble Strips on Performance of Sober and Alcohol-Dosed Subject Drivers BIBA 963-966
      Valerie J. Gawron; Thomas A. Ranney
    Accident studies have identified nighttime conditions on rural roads as particular problems for alcohol-impaired drivers. Uneventful driving is hypothesized to result in progressive degradation of tracking performance and a reduced ability to handle the demands of hazardous locations, such as curves. To address these problems, a simulated rumble strip was evaluated experimentally. Six subjects drove an instrumented vehicle over a closed course under two conditions (presence versus absence of rumble strips) and three levels of BAC (0.00, 0.07, 0.12%). The effects of the rumble strips were evaluated from both road-departure characteristics (lane departure and accident frequency, maximum distance off the road, mean time off the road per departure, time between successive departures) and overall driving performance (means and standard deviations of velocity and lateral position). Rumble-strip presence was associated with increased time between successive left-side departures, increased mean velocity, and reduced speed variability. There were no significant differences between rumble-strip presence and absence for right-side departures.
    Experimental Studies of Daytime Running Light Design Factors BIBA 967-970
      Clifford C. Baker; Mark Kirkpatrick; Christopher C. Heasly
    Data from accident rate field tests have suggested that the use of Daytime Running Lights (DRL) on vehicles may have potential for reduction of collision likelihood and severity. With regard to the possible introduction of DRL in the United States, a number of research and design issues have arisen. These involve effects of design parameters on vehicle conspicuity under daylight conditions including central lamp intensity, beam distribution, lamp area, lamp color, number of lamps, and lamp/background contrast. Experiments were conducted to determine effects of DRL design parameters on peripheral detection of an oncoming vehicle under daylight conditions, detection of operating turn signals in the presence of a masking DRL, and degree of discomfort glare produced by DRL under twilight conditions.
    Night Time Recognition of Reflectorized Warning Plates as a Function of Shape and Target Brightness BIBA 971-975
      Helmut T. Zwahlen; Daryle Jean Gardner-Bonneau; Charles C., Jr. Adams; Michael E. Miller
    Two independent studies, each employing 12 subjects sitting in a stationary car on an unused airport runway with low beams on, were conducted to determine the distance at which a shape coded, reflectorized warning plate can be recognized at night as a function of target brightness. Recognition distances were recorded for a balanced combination of 15 experimental conditions consisting of 3 different specific intensity levels of target brightness (high 1080 cd/fc/sq ft at .2 degrees observation angle an -4 degrees entrance angle; medium 305 cd/fc/sq ft and low 105 cd/fc/sq ft) and 5 different shapes of equal area (18 square inches) targets (rectangle, circle, square, triangle, octagon). Study 1 used a car heading angle of 10 degrees to the right while Study 2 used a car heading angle of -3 degrees to the left. Results of these studies indicated that increasing target brightness had either no effect or only a small effect on target recognition distance, and the triangle (the object with the longest sides) was recognized at the largest distance and with the fewest errors. Targets were also recognized further away at the 10 degree car heading angle (less beam illumination) than at the -3 degree car heading angle (near maximum beam illumination). Implications of these results for the design and display of shape coded reflectorized warning plates in both traffic and industrial settings are discussed.
    Preliminary Study of Brake Pedal Location Accuracy BIBA 976-980
      R. Quinn, Jr. Brackett; Rodger J. Koppa
    Three experiments of brake pedal location accuracy were conducted using 24 subject drivers. The first experiment tested the accuracy of recall of drivers for the brake pedal location of the vehicle with which they were very familiar. The second experiment examined the accuracy of recall for a brake pedal location with which they had recent practice. The last experiment attempted to determine if practice with one brake pedal location would interfere with the accuracy of reproduction of a newly learned pedal location. The results of the experiments indicate that subject drivers have difficulty in reproducing the location of brake pedals. This difficulty exists for familiar brake pedal locations as well as newly learned brake pedal locations. Further there is an indication that practice with one brake pedal location may influence the accuracy of reproducing the location one newly learned.

    Safety: Workplace Safety: Physical Activity and Other Tasks

    Performance, Perceived Safety, and Comfort of the Alternating Tread Stair BIBA 981-984
      Gerard C. Jorna; Michael F. Mohageg; Harry L. Snyder
    This study determined the perceived safety and comfort of an alternating tread stair and a conventional ships ladder. The alternating tread stair and the conventional ships ladder were also compared with respect to travel time and missteps. Subjects in military uniform ascended and descended both the alternating tread stair and the conventional ships ladder under load and no-load condition. In the load condition subjects performed trials while carrying a 9-kg tool box, and in the no-load condition trials were performed without the tool box. Results indicate that the alternating tread stair is perceived to be safer and more comfortable to use. Moreover, the alternating tread stair had significantly fewer missteps.
    Time Estimation Performance Before, During and After Physical Activity BIBA 985-989
      T. Mihaly; P. A. Hancock; M. Vercruyssen; M. Rahimi
    An experiment is reported which evaluated performance on a 10-sec time interval estimation task before, during and after physical work on cycle ergometer at intensities of 30 and 60% VO2max, as scaled to the individual subject. Results from the eleven subjects tested indicate a significant increase in variability of estimates during exercise compared to non-exercise phases. Such a trend was also seen in the mean of estimates, where subjects significantly underestimated the target interval (10 seconds) during exercise. Subjects also performed more accurately with information feedback than without knowledge of results, but they were still not able to overcome the effects of exercise. As suggested by the experimental findings, decreased estimation accuracy and increased variability can be expected during physical work and is part of a body of evidence which indicates that exercise and its severity has a substantive impact on perceptual and cognitive performance.
    A Safety Risk Evaluation of Vigilance Tasks in the U.S. Surface Mining Industry BIBA 990-994
      Stephen D. Hudock; James C. Duchon
    Due to the labor intensive nature of mining, the health, safety and performance of miners is critical to the success of the industry. The U.S. Bureau of Mines has conducted research on accident risk associated with performance of vigilance tasks in surface mining occupations. Over one-third of all surface mining occupations were judged to require extreme to high levels of vigilance for proper task performance. Through accident data analysis of all reported mining accidents available on the Mine Safety and Health Administration accident data base for the year 1986, it was determined that the occupational accident severity level for those employed in high-vigilance surface mining jobs was about twice that for low-vigilance surface mining occupations, based on actual days lost and statutory days charged. This difference in accident severity levels was analyzed with respect to the natures of the task activity involved. It was shown that accident severity is higher for employees in high vigilance groups, even for activities that only require low vigilance to perform. These findings support the conclusion that vigilance demands in mining represent a distinct safety risk which may persist for different types of tasks and activities.
    How Physical Work Activity and Certain Earmuff Design Attributes Influence Achieved Hearing Protection BIBA 995-999
      John G. Casali; James F. Grenell
    Laboratory tests of personal hearing protectors typically overestimate the attenuation performance of the devices in the workplace, where a number of factors reduce protection levels. This research investigated several practical factors including the influence of the user's work-related movement, and variations in headband compression force and ear cup cushion material (liquid- or foam-filled) on the noise attenuation achieved with earmuff hearing protectors. Attenuation data were collected on 24 subjects both prior-to and following completion of a simulated work task. Work-related movement was found to significantly decrease attenuation. A high compression headband provided increased attenuation, while there was no significant difference between cushion types as to protection achieved.

    System Development: Individual Differences Make a Difference in Systems Research

    Individual Differences Make a Difference in Systems Research BIBA 1000
      Janet J. Turnage
    Despite a long history within the field of experimental psychology to repudiate and even reject individual differences in statistical analyses of data by treating such differences as "within-group variances" or "error variances," the effects of individual differences on performance outcomes are tremendous. Humans vary greatly in human behavior and performance, where ranges rarely fall below 200%, and differences frequently occur in the thousands of percents (Rimland & Larson, 1986). The joint contribution of treatment and subject effects has been incorporated into new psychological theories of cognition and skill development, and has been readily accepted in applied settings such as military manpower, personnel, and training (MPT) programs.
    Individual Differences in Flight Simulation Performance Experiments BIBA 1001-1005
      Margaret D. Nolan; Lawrence J. Hettinger; Robert S. Kennedy; Katrina M. Edinger
    In a review of flight simulation performance experiments conducted at the U.S. Navy's Visual Technology Research Simulator (VTRS), it was observed that individual difference variables accounted for a major portion of the total explained variance, in many cases more than the simulator equipment variables that were deliberately manipulated. This finding underscores the importance of individual differences in performance and training research in support of man-machine systems development and implementation. The identification of the substrata underlying individual differences will impact on equipment design considerations and training program requirements for military and industrial systems.
    Cognitive/Intellectual Abilities as Predictors of Skilled Performance: Answering the Which, When and How Questions BIBA 1006-1010
      Phillip L. Ackerman; Christopher E. Sager
    Recently, there has been a re-emergence of interest in the cognitive ability determinants of individual differences in skill acquisition and skilled performance. First we review some basic characteristics of individual differences in skill acquisition. We next consider the current evidence for the emergent "task-specific" factor, a matter that may have important implications for the utility of ability measures as predictors of individual differences in asymptotic skilled performance. We also review two major factors in determining the relations between abilities and individual differences in skill acquisition, advances in theory and the enlargement of the data base for discussion of the topic. We address these factors, in the context of a discussion of "which" abilities predict individual differences in skilled performance, "when" such predictors are maximally effective, and "how" abilities and information processing demands interact to determine ability-performance associations.
    Evaluation of Cognitive Function in Aviators BIBA 1011-1015
      Alan F. Stokes; Marie T. Banich; Valorie C. Elledge; Ying Ke
    The FAA is concerned that flight-safety could be compromised by undetected cognitive impairment in pilots due to conditions such as substance abuse, mental illness and neuropsychological problems. Interest has been shown in the possibility of adding a brief "mini mental exam", or a simple automated test-battery to the standard flight medical to screen for such conditions. This paper reports an empirical evaluation of four such tests, focusing upon a prototype version of an automated screen battery, SPARTANS (Simple Portable Aviation Relevant Test-battery and Answer-scoring System).
    A Paradigm for the Identification of Independent Cognitive Constructs BIBA 1016-1020
      Jennifer E. Fowlkes; Robert S. Kennedy; William P. Dunlap; Mary M. Harbeson
    A promising approach in recent years has been to develop measures of individual differences based upon componential cognitive theory to supplement or supplant traditional measures. Cognitive tests are developed to measure theoretically based mental operations which can be isolated by the computation of derived measures such as slope and difference scores. Along with others, we believe there are impediments to this approach due to unreliability of derived measures and lack of demonstrated statistical independence of tests of cognitive abilities. This paper describes a methodology for examining measures of individual differences in information processing skills that first follows the tenets of psychometric theory and then addresses cognitive theories. The approach is illustrated by demonstrating its application in tests representing four distinct cognitive paradigms which were administered repeatedly to subjects over three weeks. Recommended direct measures and derived scores for the four paradigms were examined in terms of their stabilities, retest reliabilities, and cross-correlations. Use of these procedures revealed that 1) derived scores had reliabilities near zero, and therefore, their correlations with other variables were equally low, rendering them of little use as individual difference variables, and 2) correlations between basic or nonderived scores were as high as their reliabilities would allow, suggesting that one common factor could account for the majority of the variance. The generality of this repeated measures paradigmatic approach to the identification of individual differences in human ability is illustrated by describing its application to the evaluation of a family of video games, tests of episodic memory, and visual contrast sensitivity at different spatial frequencies.

    System Development: Defining the Human-Computer Interface

    Making Behavioral Data Useful for System Design Applications: Development of the Engineering Data Compendium BIBA 1021-1025
      Janet E. Lincoln; Kenneth R. Boff
    In spite of the critical need to match the capabilities of complex human-interfaced systems to the capabilities and limitations of the human operator, relevant research findings on human perception and performance are seldom given systematic consideration in the design of control and display systems. A major reason is that the costs and risks associated with accessing, interpreting, and applying these data are unacceptably high to designers already overburdened with technical information. To help reduce these costs, the Integrated Perceptual Information for Designers (IPDP) program has developed: (1) a procedure for compiling and integrating widely scattered human performance research data with potential application in system design; and (2) a format for presenting these data so they can be used directly by practitioners to support design decisions and trade-offs. This data consolidation procedure and presentation format have been used to produce a full-scale demonstration data resource, the Engineering Data Compendium, that integrates information from over 75 subareas of human perception and performance into a 4-volume reference work for designers.
    Spreadsheet Macros for Rapid Prototyping of Computer Interface Dialogues BIBA 1026-1030
      Richard S. Marken
    The Lotus 1-2-3 spreadsheet macro language provides a low-cost, readily accessible, and easy-to-use method for rapidly building prototypes of computer interface dialogue systems. This method of prototyping was used to evaluate specifications for the human interface component of a satellite ground control system. The prototype mimics the essential functional components of the interface dialogue, and is easily modified, making it possible to determine whether recommended changes in dialogue specifications produce actual improvements in dialogue design.
    Capturing Air Traffic Controller Expertise for Incorporation in Automated Air Traffic Control Systems BIBA 1031-1035
      Howard L. Bregman; Warren L. McCabe; William G. Sutcliffe
    Under Federal Aviation Administration (FAA) sponsorship, MITRE's Human Performance Assessment Group is contributing to the design of an expert system to support air traffic control. We are working closely with a team of expert, full-performance-level air traffic controllers to capture the formal and informal rules they use in maintaining flight safety and efficiency. This paper documents our approach to working with these experts, the results of using that approach, and a distillation of lessons learned.
    Artificial Intelligence (AI) System Interface Attributes: Survey and Analyses BIBA 1036-1040
      Denise L. Wilson; Gilbert G. Kuperman; Robyn L. Crawford; William A. Perez
    This study represents a first phase in the design of a human factors tool for artificial intelligence (AI) system assessment. Desirable attributes of AI interfaces were identified as a result of a review of the literature. A questionnaire was developed where explicit definitions were presented for 17 selected attributes. Nineteen AI system developers rated the attributes under four different context conditions: (1) no context (i.e., general application); (2) a bomber crew system; (3) a command and control station; and (4) an intelligence analyst position. Examination of the ratings showed that attributes pertaining to tasks which impose a high level of time stress received the highest ratings of importance. The ratings data were subjected to Multidimensional Scaling (MDS) analyses where the following dimensions were determined: (1) tasks performed principally by the system versus tasks requiring system-human communication; and (2) system attributes that principally require algorithmic interpretation versus those that require a high level of AI capabilities.
    A Case Study in Large Scale Computer Human Interaction Design BIBA 1041-1045
      Robert Lorenzetti; Janet Williamson; Larry Hoffman; Tim Beck; Frank Maguire
    The Reliability & Maintainability Information System (REMIS) is being developed by a team of Litton Computer Services, Tandem Computers, and SofTech under contract to the Air Force Logistics Command (AFLC) Logistics Management Support Center. Its purpose is to make accessible to AF managers worldwide, the data necessary to keep weapon systems combat ready in peace and sustain them in war. REMIS will modernize the collection and use of inventory, status, utilization, operational reliability, maintenance, configuration, mission capability, and awaiting parts data for aircraft, trainers, automatic test equipment, Communications-Electronics (C-E) equipment, and support equipment.
       The Government procurement request for REMIS envisioned the need for human engineering of the Human Computer Interface (HCI), but there were no requirements to deliver human factors analysis documentation nor to conduct any formal testing. The HCI design task was eventually assigned to an ad hoc team (Messrs. Lorenzetti, Beck and Maguire) with no formal human engineering experience, and with severe time constraints. Design of a user-friendly systems under these constraints (using available human factors data sources) proved to be a challenging exercise.
       This paper presents a description of the informal user surveys and qualitative evaluations that were used as a surrogate to the more formal approaches normally recommended. After the fact, the over 900 guidelines in Smith and Mosier were reviewed, with 75 found to be specifically applicable to REMIS. REMIS conformance to each of the 75 guidelines was then assessed. Although the REMIS design was evaluated as reasonably good, we concluded that specific human engineering requirements, schedule, budget, and documentation should be provided. The accessibility of human factors data supporting design should be substantially improved if better quality HCI's are to be assured.

    System Development: Tools for the Practitioner

    A Human Operator Model Management Environment BIBA 1046-1050
      Floyd Glenn
    Inadequacies of existing simulation and modeling tools in supporting development and evaluation of man-machine systems are considered. A new tool is proposed to support the development and use, by the end user, of a base of fundamental human performance models representing alternative factors and levels of detail. The Human Operator Model Management Environment (HOMME) is designed to aid in the construction and management of human performance models that are used as elements of larger man-machine system performance simulations. HOMME aids the user in constructing performance procedures and in defining the control interrelations between procedures, as well as in storing, retrieving, and editing procedures generated in earlier simulation efforts. It is intended to serve as an adjunct tool to the more general simulation shell known as HOS-IV.
    Everything You Always Wanted to Know about HOS Micromodels but Were Afraid to Ask BIBA 1051-1055
      Regina M. Harris; Helene P. Iavecchia; Alvah C., Jr. Bittner
    HOS-IV is a general purpose simulation tool for modeling human operators, systems and the environment. To build a simulation, inputs to the model typically include descriptions of the system design, procedures for using the system, human operator characteristics, and a mission scenario. A set of operator micromodels are available to the HOS user to assist in the development of the simulation. These micromodels contain algorithms, based on experimental literature, that can predict the timing and accuracy of basic human cognitive, perceptual, and psychomotor actions. This paper describes the current set of human performance models available in HOS-IV as well as micromodels planned for development.
    Manpower Constraints Aid (M-CON) and Personnel Constraints Aid (P-CON) BIBA 1056-1059
      Larry O'Brien
    This paper describes the Manpower Constraints Aid (M-CON) and the Personnel Constraints Aid (P-CON). Both aids are being developed under the Army Research Institute's (ARI's) project to develop improved MANPRINT methods. The M-CON Aid and P-CON Aid will assist Army analysts in producing estimates of manpower and personnel constraints during the earliest phases of the acquisition process. These constraints will be incorporated into requirements documents, system specifications, and MANPRINT target audience descriptions.
    A Manpower Determination Aid Based upon System Performance Requirements BIBA 1060-1064
      K. Ronald, Jr. Laughery; Susan Dahl; Jonathan Kaplan; Rick Archer; Gail Fontenelle
    This paper discusses two of the six software tools which are being developed as part of the Army Research Institute's MANPRINT Methods development program. The first tool discussed here is known as the System performance and RAM Constraints Aid or SPARC. This tool permits system designers to determine levels of subfunction performance which are required to achieve function and higher level mission requirements. These levels of subfunction and function performance then serve as requirements which are fed into the second tool, the Manpower Systems Evaluation Aid (MAN-SEVAL). MAN-SEVAL takes as input the system design and then predicts the operator and maintainer manpower required to achieve the required levels of task and function performance. For maintenance manpower evaluation, MAN-SEVAL considers component failure rates, time to perform maintenance, and the mission scenario. For operator manpower and to estimate maintenance task times, MAN-SEVAL conducts an analysis of workload, control/display accessibility, and maximum acceptable performance time to allocate tasks across crewmembers. Because all manpower requirements are truly driven by system performance requirements, these two tools are being developed collectively with common data bases and software design. While they are currently being developed for the Army, they will be useful general purpose manpower analysis tools.
    Personnel-Based System Evaluation Aid (PER-SEVAL) BIBA 1065-1067
      Larry O'Brien
    This paper describes the Personnel-Based System Evaluation Aid (PER-SEVAL), one of the automated tools being developed under the Army Research Institute's project to develop improved MANPRINT methods. The PER-SEVAL Aid will assist Army analysts in identifying the quality of personnel needed to support a particular contractor's design.

    System Development: Tools, Testbeds, and Prototypes

    The Workload Assessment of a Mobile Air Defense Missile System BIBA 1068-1072
      Susan G. Hill; Allen L. Zaklad; Alvah C., Jr. Bittner; James C. Byers; Richard E. Christ
    Four operator workload (OWL) scales were retrospectively applied to crewmembers of a mobile air defense missile system, LOS-F(H), following a candidate-selection field evaluation: NASA TLX, SWAT, Overall Workload (OW), and the Modified Cooper-Harper (MCH). Jackknife factor analysis revealed the presence of only a single factor (explaining 79.6% of the total variation) and indicated a significant (p<.0075) ordering of the mean factor loadings: TLX (.935) and OW (.927) were significantly greater than MCH (.862) and SWAT (.860). Comparison with an earlier field test of a remotely piloted vehicle revealed a significant (p<.00005) interaction of test and ordering of the OWL scales, but TLX and MCH consistently had the respectively highest and lowest loadings across the two field tests. Multiple correlation also revealed a significant (p<.0001) relationship, R = 0.66, between system performance and TLX. These findings and lessons learned are discuss in the context of the development and validation of a methodology for assessing OWL.
    The Development of the Air Anti-Submarine Warfare Mission Testbed as a Tool for the Development of Operator Models BIBA 1073-1077
      Wayne W. Zachary; Monica C. Zubritzky; Floyd A. Glenn
    The central concern of human factors engineering (HFE) is facilitating a productive relationship between man and machine. A new generation of man-machine systems has arisen in which the machine acts in a relatively intelligent manner to enhance the operator's decision-making capabilities in real-time multi-tasking situations. These systems have been termed "distributed intelligence systems" (DIS) because intelligence is distributed among all system entities, whether they are human or computer. The ability of these systems to aid humans in a flexible, interactive fashion depends on the capability of the machine to predict the human's information needs in a given decision-making situation. Thus, the DIS must incorporate a model that reflects the operator's information processing requirements for the tasks necessary to operate the system. Of construct this model, it is necessary to develop a DIS testbed where experimental investigations can occur. The mission environment chosen for simulation is the Naval Air Anti-Submarine Warfare (ASW) mission, whose objectives to search for, find, and attack the enemy submarine involve complex tactical decisions in a real-time multi-tasking environment. In the Air ASW mission, most significant tactical decisions are made by the Tactical Coordinator (TACCO), the main operator of the system. The aspects of the testbed discussed in this paper include those elements of the simulation and responsibilities of the TACCO needed to illustrate the types of information processing tasks involved in the ASW mission. Also, the data collection capabilities of the testbed and how this data will be applied to operator model development will be discussed.
    A Concept Evaluation of an Electronic Delivery of Maintenance Information BIBA 1078-1081
      Michelle R. Sams; Joel H. Fernandez
    This study evaluated the concept of using electronically delivered technical procedures to support maintenance operations in lieu of paper feasibility, and human factors issues. The Electronic Maintenance Publication System (EMPS) was tested on the PATRIOT system, an air defense missile system. No significant difference in maintenance time was found between EMPS or paper manuals. Errors committed while performing the tasks were negligible. Human factors issues were considered primarily to evaluate the concept of an electronic delivery and to guide refinement and future development of the system. Based on this study, it was concluded that an electronic delivery of maintenance information (as tested in EMPS) is an effective and feasible alternative to paper publications.
    Use of a Crew Display Demonstrator to Evaluate Combat Vehicle Command and Control System Concepts BIBA 1082-1084
      Sam R. Hollingsworth; Mark B. Mikula
    The U.S. Army Tank Automotive Command (TACOM) has developed a Vetronics Crew Display Demonstrator (VCDD) to aid in the design of crew-such vehicles in future land combat vehicles. One major component of which will be combat vehicle command and control (CVC2) system, which will include innovative navigation and communication functions. The VCDD has been configured to simulate a range of CVC2 system concepts that vary widely in appearance and method of crew-system interaction. Use of the VCDD has provided TACOM with insights into the potential benefits of alternative CVC2 system concepts, and will support continued development of CVC2 system requirements.
    A Militarized System with Complete Control Exercised Without Hardware Switches BIBA 1085-1089
      Michael Maher
    This paper describes the Man-Machine Interface for a militarized radar system. The interface strives to achieve high reliability in terms of both hardware and operator performance, and allows a single operator the ability to control all aspects of the radar system. To accomplish this, a computer controlled touch input design has been assembled, is being tested, and can be fielded in the early 1990's. Reduction in operator fatigue and increases in operator proficiency are combined with the capabilities to minimize required training time and money, provide a system capable of cost effective updates and growth along with the ability for rapid, real time reconfiguration due to failed electronics or changing battlefield conditions.

    System Development: Human Factors in Navy Systems

    Human Factors in the Space and Naval Warfare Command: Display System Standardization BIBA 1090-1094
      Phillip J. Andrews; Thomas B. Malone; Kathryn E. Permenter; David R. Eike
    This paper describes the state and status of human factors within the Space and Naval Warfare Command (SPAWAR) by focusing on a major effort currently being pursued within SPAWAR, that of developing a standard workstation design concept for Navy applications. Human factors concerns were paramount in the assessment of requirements for a standardized workstation applicable to Navy-wide requirements. The major human factors concern was display usability.
    Human Factors in the Naval Air Systems Command: Computer Based Training BIBA 1095-1099
      Thomas L. Seamster; Cathrine E. Snyder; Michele Terranova; William J. Walker; D. Todd Jones
    Military standards applied to the private sector contracts have a substantial effect on the quality of Computer Based Training (CBT) systems procured for the Naval Air Systems Command. This study evaluated standards regulating the following areas in CBT development and procurement: interactive training systems, cognitive task analysis, and CBT hardware. The objective was to develop some high-level recommendations for evolving standards that will govern the next generation of CBT systems. One of the key recommendations is that there be an integration of the instructional systems development, the human factors engineering, and the software development standards. Recommendations were also made for task analysis and CBT hardware standards.
    Human Factors for Naval Systems: Enhanced HARDMAN BIBA 1100-1103
      Thomas B. Malone; Clifford C. Baker
    The U.S. Navy is developing methods for integrating the disciplines concerned with personnel considerations into the weapon system acquisition process. This integration essentially involves human factors engineering, manpower, personnel and training, and life support engineering. Since the Navy already has the in system development, the process of integration of personnel issues will involve expanding the HARDMAN methods and data to include human factors engineering and life support engineering, resulting in the Enhanced HARDMAN process. This paper describes the objectives of Enhanced HARDMAN.
    Human Engineering in the Naval Sea Systems Command BIBA 1104-1107
      Thomas B. Malone; Clifford C. Baker; Kathryn E. Permenter
    This paper describes the status of human engineering in the Naval Sea Systems Command (NAVSEA). NAVSEA has pursued four major thrusts in the development and application of human engineering technology: 1) human engineering research and development efforts, 2) human engineering front-end analysis, 3) human engineering audits as part of the Logistic Review Group (LRG) formal review of each program, and 4) ship and ship system engineering design and evaluation. This paper describes the progress that NAVSEA has made in each area.

    System Development: System Development Applications

    MANPRINT in the Program Initiation Phase of System Acquisition BIBA 1108-1112
      Thomas B. Malone; Randy M. Perse; Christopher C. Heasly; Mark, III Kirkpatrick
    For the U.S. Army Human Engineering Laboratory (USAHEL), Carlow Associates recently completed development of the MANPRINT Integrated Decision/Engineering Aid (IDEA) for the Program Initiation Phase of system development. The IDEA includes a standard MANPRINT process describing activities, events and products for the Phase, a decision aid and analyst's workstation to support the Program Initiation Phase. Specific tools included in IDEA are: 1) an early comparability analysis tool (ECA) which provides baseline system lessons learned and high MANPRINT drivers, 2) an automated task analysis tool, 3) an allocation of function tool which enables and supports the determination of the required role of the soldier in the system, and 4) a workload and human performance simulation tool based on a task network and probabilistic process variables. Efforts involved in the MANPRINT process development addressed the integration of the activities and products of Human Factors Engineering (HFE), Manpower, Personnel and Training (MPT), and System Safety (SS) and Health Hazard Assessment (HHA) with the activities of the Material Acquisition Process (MAP), and identification of MANPRINT technology requirements to support the application of this process.
    Determination of Program Initiation Phase MANPRINT Requirements for the Lighter, Amphibious Heavy-Lift (LAMP-H) BIBA 1113-1116
      Christopher C. Heasly; Kathryn E. Permenter; Thomas B. Malone; Clifford C. Baker; Louis G. Lawrence
    The objective of this paper is to describe the approach utilized in the development of MANPRINT requirements for the Lighter, Amphibious-Heavy Lift (LAMP-H). LAMP-H is an air cushioned vehicle with a crew of six: a pilot, a navigator, and four stevedores who load and unload equipment from the vessel. The project was initiated during the program initiation phase of development. Several types of Air Cushion Vehicle (ACV) lighter craft were evaluated as baseline comparison systems for LAMP-H. The effort involved insuring compliance with human engineering design criteria and practice, incorporating lessons learned from analogous air-cushioned vehicles lighter craft, and addressing habitability, noise and other design issues affecting crew performance of tasks critical to the operation and maintenance of the LAMP-H. This paper details the analyses and techniques implemented in the early phases of the weapon system acquisition process for designing improved soldier-machine systems, as well as the products of the effort.
    Application of HARDMAN II Methodology to the Army's Forward Area Air Defense (FAAD) System BIBA 1117-1121
      John E., II Stewart; Uldi Shvern
    HARDMAN II, an automated form of HARDMAN (Hardware vs. Manpower) analysis was applied to two new Army air defense systems for purposes of estimating maintainer workload and maintenance manpower requirements. Estimates showed a shortfall in official manpower allocations. Partially as a result of the HARDMAN II analyses, the Army decided to add more maintainers to the organization supporting both systems.
    Workload Assessment Aid for Human Engineering Design BIBA 1122-1125
      Gail Fontenelle; K. Ronald Laughery
    The Workload Assessment Aid (WAA) is a software tool developed for the Army Research Institute as part of the MANPRINT effort. This software toolkit is specifically designed to predict operator workload at the earliest stages of design. It builds upon a task network simulation tool, Micro SAINT, by incorporating several other predictive workload techniques, in addition to several new dimensions. In it final form the tool will automatically make these task re-allocation recommendations based on workload profiles, personnel characteristics and display-control accessibility.
    Integrating Human Engineering into the Design of the User Interface of a Large Scale System BIBA 1126-1130
      Daniel T. Wick
    This paper proposes allocating to user and developer organizations a portion of the human engineering required to design a user interface of a large scale system. The integration of the human engineering activities and the benefits realized by both organizations are discussed.

    Test and Evaluation: Workload Evaluation: Technique and Application

    A Physical Measure of Subjective Workload BIBA 1131-1135
      David W. Biers; Donald J. Polzella; Paul McInerney
    This investigation compared a physical measure of subjective workload (i.e. hand dynamometer) with traditional verbal scaling techniques. There were four subjective rating groups. One group employed the Subjective Workload Assessment Technique (SWAT) which required three separate ratings of time stress, mental effort, and psychological stress. A second group used verbal magnitude estimation (ME). Two physical measure groups estimated the magnitude of workload by squeezing a dynamometer in accordance with the magnitude of workload experienced. The DYNA1 group made one overall rating of workload similar to the ME group. The DYNA3 group made three workload ratings along the same dimensions as SWAT. All groups rated the workload associated with the performance of a continuous memory task under twelve levels of task difficulty. The physical measure of subjective workload most closely corresponded to actual task performance differences. The results suggest future development of a physical measure of subjective workload which can be utilized on a continuous basis, thus avoiding a major shortcoming of typical verbal measures of subjective workload.
    An Alternative to Measuring Subjective Workload: Use of SWAT Without the Card Sort BIBA 1136-1139
      David W. Biers; Paul McInerney
    One major drawback in some applications of the Subjective Workload Assessment Technique (SWAT) is the time required to administer the card sort. There are alternative methods of forming a workload composite from the SWAT instrument (i.e. a simple sum of the three scales or composite derived from multivariate statistics) which do not require the card sort. The present study compared the sensitivity of these alternative SWAT composite measures with the typical SWAT conjoint scaling metric which requires the card sort. A two group study was conducted in which subjects engaged in a continuous recognition task under twelve levels of task difficulty. One group (Pre-Task), performed the card sort prior to engaging in the task whereas in the other group (Post-Task) completed the card sort subsequent to task performance. Results indicated that placement of the card sort did not affect the task ratings on the three dimensions of SWAT nor did it affect the relative sensitivity of the three workload composites. All three composite measures were found equally sensitive to the task demands. These results indicate that the SWAT instrument can be used to effectively measure workload without having to perform the card sort.
    Arousal Effects on Cognition: New Strategy which Isolates Movement and Heart Rate Effects Inherent in Physical Work BIBA 1140-1144
      Tina Mihaly
    Most experiments which have sought to determine the effects of arousal, exercise and/or physical work on psychomotor performance have been tainted by methodological problems. This paper presents a strategy that was developed to overcome one methodological shortcoming inherent in many such studies: the confounding of movement and heart rate. The technique involves administering mental tests during both movement and non-movement intervals, at pre-selected exercise states. Results of a validation experiment, in which 11 subjects performed numerous psychomotor tasks with and without movement at four work intensities (rest, 30% VO2max, 60% VO2max, and post-exercise) on two testing days indicate that this method was sufficiently sensitive to identify previously undetected effects, e.g., movement slows index finger tapping rate and may impair an individual's ability to stabilize speed-accuracy tradeoff strategies in serial choice reaction time tasks. Inverted-U effects were also found, replicating some previous investigations. The novel strategy detailed herein, which isolates the relative effects of movement and elevated heart rate, appears appropriate for use in studies aimed at quantifying the effects of exercise-induced arousal (via cycle ergometry) on mental performance before, during and after exercise. This work has implications for improving research methodologies and predicting which sorts of everyday speeded mental tasks will be affected when one is simultaneously engaged in physical work.
    Workload Assessment of a Remotely Piloted Vehicle (RPV) System BIBA 1145-1149
      James C. Byers; Alvah C., Jr. Bittner; Susan G. Hill; Allen L. Zaklad; Richard E. Christ
    Four empirical operator workload (OWL) scales were applied to ground control operations of the Aquila RPV during a recent field test: NASA TLX, SWAT, Overall Workload (OW), and the Modified Cooper-Harper (MCH). Seventeen sets of individual assessments of mission segments were made by the four members of each of four crews and one replacement crewman. "Jackknife factor analysis" revealed the presence of only a single factor and indicated that the mean factor loadings formed a consistent ordering (F(3,48) = 503.5, p<.00005): TLX (.910) > SWAT (.893) > OW (.869) > MCH (.833). ANOVAs also examined the effects of various variables on the composite workload factor scores; significant findings were found which reflected both upon the system and its test. These findings as well as informal lessons learned are discussed in the context of the development and validation of a methodology for assessing OWL.

    Test and Evaluation: Test and Evaluation in Operational Settings

    Effects of "Workarounds" on Perceptions of Problem Importance During Operational Test BIBA 1150-1153
      John F. Courtright; William H. Acton; Michael L. Frazier; J. Walter Lane
    Workarounds are nonstandard procedures operators devise to compensate for system deficiencies. This study investigated the impact of workarounds on the perceived importance of problems discovered during operational test. Questionnaire data were collected for 73 reported design deficiencies to assess the existence and effectiveness of workarounds and the importance of the tasks they affected to mission success. Problems were viewed as more important when workarounds were ineffective or time consuming, and when the tasks affected were deemed critical to mission success. Implications for problem prioritization are discussed.
    Task Familiarity Effects on Job Sample Performance BIBA 1154-1158
      Kristina S. Weeden; Virginia M. Berry; Herbert George Baker
    As part of the Navy Job Performance Measurement Program, the technical proficiency of first-term radioman (RM) personnel was measured using a multimethod approach, the most significant component of which was a hands-on, or job sample test. Because the RM job included large number of personnel assigned to both ships and shore installations, the performance of these two groups on the hands-on test was compared and related to achievement on the other measures. The data were analyzed using MANOVA to test the overall difference between the groups across 12 hands-on task tests, showing that RMs assigned to ships performed significantly better than RMs assigned to shore installations. T-tests for each of the task tests showed that RMs assigned to ships performed significantly better than RMs assigned to shore installations on seven of the 12 task tests. Examinations of personnel background questionnaire information revealed a significant difference in the work experience between the groups. Possible causes of the assignment effects are discussed.
    Application of a Cost-Benefit Model to the Evaluation of a Military Training Management Information System BIBA 1159-1161
      Thomas F. Sanquist; Marvin C. McCallum
    A method to facilitate the comparative evaluation of automated systems based on quantitative predictions and measurements of system impacts is described. A model of the costs and benefits resulting from the automation of U.S. Army training management activities was developed on the basis of work function taxonomy measures. Data were collected from a sample of 66 personnel in the 9th Infantry Division to determine the time spent on different job tasks and work functions. The savings that could be obtained through automation were estimated by applying workload reduction factors to the task and work function times estimates. The estimates were extrapolated to the entire Army to determine the impact of a fully fielded system. The results indicate that the Army currently spends 8208 person-years on training management at a cost of $348 million. Automation could potentially reduce these cost to 5683 person-years at a cost of $227 million. The potential savings of $121 million represent resources that are currently consumed by inefficient procedures. This methodology is useful for generating quantitative predictions of automation impact for verification in comparative evaluations.
    Test and Evaluation of an Air Force Non-Developmental Item (NDI) Computer System BIBA 1162-1165
      Robert Simon; Martha A. Schmidt; Nancy Courville
    The Air Force is fielding a computer-based command and control system to support fighter base mission requirements. The acquisition strategy for this system was to purchase it as a Non-Developmental Item (NDI). Since the hardware and software were in the Air Force inventory, it was determined that system development was not necessary. Initial implementation and installation occurred without system-level specifications or performance requirements. This paper presents the results of a Human Factors Engineering evaluation of the system from three perspectives: an Expert's view, a Military Standard view, and a User's view. Two primary lessons resulted from the evaluation: First, the multi-perspective evaluation technique is valuable and highly recommended for use in other HFE evaluations. Second, the purchase of NDI or commercial off-the-shelf (COTS) items should be viewed from the systems perspective, i.e., even though subsystems may be NDI, the system may be developmental.

    Test and Evaluation: Panel

    Innovative Approaches to Human Factors in Operational Test and Evaluation BIBA 1166-1168
      Bettina A. Babbitt; Gregory S. Krohn; Sally A. Seven; Douglas K. Spiegel; Charles O. Nystrom; David Meister; Frederick A. Muckler
    Each year, it would appear that more and more human factors specialists participate in and support system operation test and evaluation (OT&E). Collecting human factors data in OT&E is particularly exciting since this is often the first opportunity to see how the system works under conditions that approximate the eventual operational environment. It is also a time to see how well the human operator/maintainer can perform within the system, what human factors deficiencies exist, and how well the human-machine interface works to create effective system performance.

    Test and Evaluation: Innovative Approaches to Human Factors in Operational Test and Evaluation

    Operational Reality and Human Factors Measurement BIBA 1169-1173
      David Meister
    This paper attempts to develop a theoretical foundation specifically for human factors measurement. The notion is advanced that reality for the discipline is the operational system. This has significant implications for human factors research.

    Test and Evaluation: New Methodology for Test and Evaluation

    The Role of Screening Studies in Sequential Research Designs BIBA 1174-1178
      Douglas B. Beaudet; Robert C. Williges
    A screening study is an economical method for analyzing a large number of independent variables using a relatively small number of data points. The role of screening studies in sequential designs is discussed and demonstrated. The methodology for selecting variables, choosing an experimental design, and collecting data is presented by reviewing the results of a recent study. The screening study was conducted using a Hadamard matrix to investigate the effects of 16 variables on a telephone information system which uses synthetic speech as the display modality. Only 32 data points were required to evaluate 16 factors in the screening study. The results of this study are discussed in terms of strategies to conduct efficient sequential research in human factors.
    A Systematic Method for the Selection of Independent Variables in the Investigation of Complex Systems BIBA 1179-1182
      P. Jay, Jr. Merkle; Douglas B. Beaudet; Robert C. Williges; David W. Herlong; Beverly H. Williges
    This paper describes a systematic methodology for selecting independent variables to be considered in large-scale research problems. Five specific procedures including brainstorming, prototype interface representation, feasibility/relevance analyses, structured literature reviews, and user subjective ratings are evaluated and incorporated into an integrated strategy. This methodology is demonstrated in the context of designing the user interface for a telephone-based information inquiry system. The procedure was successful in reducing an initial set of 95 independent variables to a subset of 19 factors that warrant subsequent detailed analysis. These results are discussed in terms of a comprehensive sequential research methodology useful for investigating human factors problems.
    Weber's Ratio, Multidimensional Scaling and Incomplete Data Sets: New Light on an Old Problem BIBA 1183-1187
      J. G. Kreifeldt; S. H. Levine; M. C. Chuang
    Sensory modalities exhibit a characteristic known as Weber's ratio which remarks that when two stimuli are compared for a difference: (1) there is some minimal nonzero difference which can be differentiated and (2) this minimal difference is a nearly constant proportion of the magnitude of the stimuli. Both of these would, in a typical measurement context, appear to be system defects. We have found through simulation explorations that in fact these are apparently the characteristics required by a system designed to extract an adequate amount of information for an incomplete observation data set according to a new approach to measurement.
    Measuring Association for Nominal Data: Alternative Derivation and Interpretation of Lambda BIBA 1188-1190
      Tarald O. Kvalseth
    Using the deviation-from-the-mode index of variation for categorical data, a measure of associate for numerical variables is derived. This measure (R²) gives exactly the same numerical results as the popular lambda measure, but their derivations and operational interpretations differ. While lambda is based on a proportional-reduction-in-error logic, R² is based on a proportional-reduction-in-variation logic analogous to the coefficient of determination for quantitative variables. Both asymmetric and symmetric R² are considered.
    An Innovative Nonparametric Measure of Response Bias BIBA 1191-1195
      William D. Shontz
    A nonparametric technique for assessing the effects of response bias within the Signal Detection Theory paradigm was developed. The technique involves modification of the 2 x n table produced when rating scale data are collected under the SDT paradigm. A X² value computed from the modified table is used as the unit of analysis in statistical analyses. This new measure of response bias has been shown to be independent of several nonparametric measures of sensitivity when tested under three different experimental designs.

    Training: Military Training Data Bases

    Military Training Data Bases BIBA 1196-1197
      G. Gary Boycan; G. Thomas Sicilia; Steve Duncan; Jim Henris; Ray S. Perez; Ok-Choon Park; James Harris
    The military is conducting research on data bases to improve training, and is establishing data bases to support operational training, research and development in training issues, and the dissemination of information concerning training. This panel presents some examples of the developmental issues in designing and establishing some data bases, and information on how to use extant data bases. Some of the data bases are interservice, such as the ones to be described by panelists from the Training Performance and Data Center (TPDC). Other focus on Army training issues and data.
    Developing a Training Data Architecture that Ties It Altogether BIBA 1198-1201
      G. Thomas Sicilia
    Everyone involved in quantifying the human part of the defense equation has long been frustrated by lack of consistent, "reproducible" and comprehensive data. This void is especially evident in the training and performance data area. The Defense Training and Performance Data Center (TPDC) was established to help redress this problem.
    Occupation Data Base Planning and Design BIBA 1202-1206
      C. Steven Duncan; Peter M. Greenston
    The Occupation Data Base under development at TPDC consists of three files. The first file describes military occupations, providing information about the attributes of the occupation. It addresses the question: what does the occupation look like? The second file describes the occupations from a "demographic" perspective, or more simply put, answers statistical profile (current and historical) of the characteristics, experience, and behavior of the people serving in each military occupation. The third file provides a data file on training programs, resources, methods and media as these elements relate to military occupations. All occupations within the enlisted, warrant officer, and officer communities are covered in each service, both active and reserve components. These three files are being built from current and historical data and will be updated regularly, thereby providing a comparative perspective with which senior service planners can make informed decisions on defense training issues.

    Training: Performance Assessment Techniques and Applications

    Development of an Air Combat Performance Measure BIBA 1207-1211
      Gary S. Thomas; David C. Miller
    The purpose of this research was to formulate a unitary measure of performance of simulated one-versus-one, within visual range, air-to-air combat. The measure will serve as a criterion for the development and validation of specific measures of ACM skill that can be used to provide diagnostic performance feedback to pilots. Two experiments were conducted in which fighter pilots served as judges and rank-ordered, from most to least desirable, hypothetical ACM engagement outcomes. Outcome variables included (1) whether or not the hypothetical pilot achieved a "kill", (2) whether or not he survived the mission, (3) the percent of time the pilot was in an offensive, defensive, or neutral posture, (4) length of engagement, and (5) posture at the beginning and end of the engagement (offensive, defensive, or neutral). In order to determine inter-rater agreement among judges in Experiment I, their rankings were correlated. Correlations ranged from .93 to .99. Pilots' rankings of engagement outcomes were subjected to linear regression analyses to derive equations that could be used as a unitary measure of ACM success. The regression equation in Experiment I accounted for 95% of the variance in rankings, and the composite regression model calculated in Experiment II accounted for more than 70% for the variance.
    Student Performance Evaluation for a Simulation Based Intelligent Expert Tutoring System BIBA 1212-1216
      C. H. Lee; J. E. Biegel; C. M. Dixon
    Intelligent tutoring systems offer an exciting new way to train people in areas of complex domains. A simulation-based training system provides the student with the opportunity to manipulate a system without the consequences of real life mistakes. The intelligence required in the tutoring system is focused on the tutor's ability to teach the student efficient, strategic responses. This tutoring demands that the tutor is aware of the student's current ability, specific fault areas, and preferred method of tutoring. Instructional decisions are made by assessing the student's performance. The utility of an intelligent tutoring system depends on its capacity to evaluate the student's performance. Performance assessment then has significant impact on the employment of such a system. The parameters used for performance assessment of a complex task depend on the objective of the tutoring system. We present a description of a generic intelligent tutoring system which will remove the human instruct or from the training loop.
    Performance Based Design of Training Programs with Moment to Moment Performance Measures BIBA 1217-1221
      Edward Connelly
    Task performance can directly impact on unit/system effectiveness and also indirectly by limiting the performance of other tasks. When assessing the impact of candidate systems designs, training programs, changes in doctrine, MOS staffing, etc., the total impact of task performance must be known. A method for calculating the total impact i.e., both direct and indirect effects, is described here in terms of the unit/system/task relationship.
    Development of a Prototype Performance Measurement System for Strike Warfare Training Assessment BIBA 1222-1226
      J. I. Martin; S. T. Breidenbach; A. P., Jr. Ciavarelli
    This paper describes methods for developing automated performance measurement systems used with training ranges and simulators. A prototype automated measurement system designed to assess aircrew performance during strike warfare training is presented as an application of this methodology. Methods are also presented for displaying information which is useful in assessing student progress and for diagnosing training results.

    Training: Approaches to Skill Acquisition

    Application of Automatic/Controlled Processing Theory to Training Tactical Command and Control Skills: 1. Background and Task Analytic Methodology BIBA 1227-1231
      Arthur D. Fisk; F. Thomas Eggemeier
    In this paper we briefly highlight relevant laboratory research that provided the theoretical and empirical underpinnings for the development of a task-analytic training methodology. The actual task-analytic methodology, developed to decompose tasks performed to support tactical command and control (C²), air-weapons controller missions, is briefly discussed. The present paper provides the necessary background for the actual application of the methodology. The details of the direct application are presented in a comparison paper by Eggemeier, Fisk, Robbins, and Lawless (1988).
    Application of Automatic/Controlled Processing Theory to Training Tactical Command and Control Skills: II. Evaluation of a Task Analytic Methodology BIBA 1232-1236
      F. Thomas Eggemeier; Arthur D. Fisk; Richard J. Robbins; Michael T. Lawless
    Automatic/controlled processing theory maintains that the consistent components of complex skills improve most substantially with training, and that part-task training (PTT) programs should therefore focus on the consistent elements of skilled performance. As an initial step in applying automatic processing principles to PTT, Fisk and Eggemeier (1988) developed a task analytic methodology to identify the consistent components of complex skills. This paper describes the application of the methodology to operator skills required in a complex tactical command and control (C²) system. The results indicate that the methodology can be used to identify a variety of consistent components of complex performance. Possible applications of PTT and issues for future training research are discussed.
    Computer-Based Job Aids which Adapt to Technician's Skill Level BIBA 1237-1240
      J. Peter Kincaid; Richard Braby; John E. Mears; A. J. G. Babu
    This paper describes current developments in automating the processes to author technical information (TI) and deliver it using microcomputers. It describes desirable characteristics which support the presentation of TI for technicians varying in skill levels. Addressed are human factors issues relating to information access, user acceptance, and display formats. Programming is being done in Smalltalk/V, an object oriented language, on a Zenith 248 computer, which is compatible with the IBM PC/AT. The project emphasizes low cost authoring and delivery of information which traditionally has been contained in paper technical manuals. Our intent is to support the Department of Defense initiative to shift paper to paperless technical manuals.
    Declarative and Procedural Knowledge in Skill Acquisition: An Aptitude-Treatment Interaction Framework for Training BIBA 1241-1245
      Phillip L. Ackerman; Ruth Kanfer
    This paper focuses on the interactions among four constructs during skill acquisition: (1) the dynamic changes in attentional demands of the task to be acquired, (2) individual differences in cognitive and intellectual abilities, (3) conative (motivational), metacognitive process involved in changes of attentional focus, and (4) knowledge structures acquired through part-task training. An attentional model is reviewed that describes how these variables interact during three phases of skill acquisition (i.e., during declarative knowledge, knowledge compilation, and at the level of proceduralized knowledge). Empirical demonstration of the framework is provided in the context of complex skill acquisition. Supportive results from a series of empirical studies are reviewed.

    Training: Training System Design -- Techniques and Issues

    The Formative Evaluation of a Decision Support System for Designing Training Devices BIBA 1246-1250
      Michael J. Singer; Randall J. Mumaw; Elizabeth L. Gilligan
    Formative evaluation in the broadest sense refers to the measurement of some system in order to make direct and immediate differences in the procedures, mechanisms, and goals of that system during development. ?The objective of this formative evaluation is to address three areas: 1) increase our understanding of how the targeted users make decisions, 2) train the user about how the system makes decisions and present information, and 3) develop information about interface and modeling changes needed in the system. What is needed in the design of decision process, and how the decisions actually could be effectively made. Both of these issues must be addressed before the user will accept and use the decision aid. The system also needs to be able to accept and use the information that the user considers necessary, as well as to present both recommendations and supporting information in acceptable formats. We have applied a structured interview within our formative evaluation process as a basis for integrating the user in the develop, revise, and deliver cycle. The structured interview vs conducted on-line, demonstrating what the system does while explanations of how it works are provided. The responses have provided information about whether the user thinks the system addresses the correct issues, the users agreement with the system analyses, and a report of the users decision processes. By including the user in the review of the developing system, the design of the prototype more accurately reflects the user's decision processes, as well as providing more usable output. This study will provide some insight about one method for evaluating decision aids early in the development process.
    Manpower, Personnel, Training and Safety in Air Force Weapon Systems Acquisition BIBA 1251-1255
      Kenneth W. Potempa; Frank C. Gentner
    Manpower, personnel, training and safety (MPTS) analysis is currently inconsistent and incomplete in its application to Air Force acquisitions. While many problems are managerial, MPTS analysis also suffers from a lack of adequate tools and data bases to analyze weapon system design, project MPTS requirements and suggest trade-offs. These problems are particularly acute in the early phases of the weapon system acquisition process (WSAP), making it difficult to influence design during this critical period. To improve MPTS analysis, a study is being conducted by the Air Force to define a comprehensive and integrated MPTS analytic system for use in the WSAP. The study is identifying what MPTS decisions need to be made in the WSAP, when they need to be made, and how they are interrelated. Current capabilities are then being determined by analyzing the tools and data bases available to support each MPTS decision. The analysis will identify needed improvements to existing tools and data bases and whether new one need to be developed. This paper discusses the requirement for an improved MPTS systems and then describes a variety of managerial and technical initiatives being undertaken to satisfy the requirement. The last section identifies the desired characteristics of an effective MPTS system.
    Developing Embedded Training (ET) Design and Integration Concepts for All Source Analysis System/Enemy Situation Correlation Element (ASAS/ENSCE) BIBA 1256-1260
      Debra C. Evans
    This paper describes the lessons learned from applying embedded training guidelines currently under development to a testbed system. The testbed system was the All Source Analysis System/Enemy Situation Correlation Element (ASAS/ENSCE). The major results of this effort was the modification of the ET guidelines to better support embedded training development.

    Training: Transfer of Training Paradigms and Learning Theory

    Simulator Evaluation of Instructional and Design Features for Training Helicopter Shipboard Landing BIBA 1261-1265
      Daniel J. Sheppard; Sherrie A. Jones; Daniel P. Westra; Joyce J. Madden
    The effects of four instructional issues and one simulator design feature for training helicopter shipboard landing on small ships were tested in the Vertical Take-off and Landing Simulator (VTOL) at the Visual Technology Research Simulator (VTRS), Naval Training Systems Center. They were: (1) field of view (VTRS versus a test field of view), (2) task chaining (segmented backward chaining versus whole task training), (3) augmented cueing (augmented cueing versus no augmented cueing), (4) length of training (18, 27, and 36 trials), and (5) the timing of seastate introduction (early versus late). The experiment utilized an in-simulator transfer-of-training paradigm in which pilots who were not proficient in the helicopter shipboard landing task were trained under one of several experimental conditions, then tested on the transfer condition (that represented maximum realism) in the simulator. Thirty-two pilots each completed a total of 54 trials (36 training, 18 transfer). Pilots were tested in the transfer condition (six trials) after their 18th, 27th, and 36th training trial. Of the experimental instructional issues, task chaining had the largest effect, with better performance in all segments of the task for pilots who were trained with the backward-chaining sequence, than for pilots who received whole task training. Augmented cueing did not yield the transfer performance anticipated. Seastate introduction had no effect on performance. Field of view had some marginal effects on vertical performance in the hover, with better performance for pilots who were trained with the combination VTRS field-of-view and backward-chaining. Results suggest a diminished rate of learning after 33 simulator trials (includes 27 training trials and six transfer trials of the first probe).
    Fidelity of Task Structure as a Guiding Principle in the Development of Skill Trainers Based Upon Complex Computer Games BIBA 1266-1270
      Daniel Gopher; Maya Weil; Tal Bareket; Sigal Caspi
    Fidelity of task structure is proposed to replace physical fidelity, as a cost effective guiding principle in the development of trainers for complex tasks. The paper describes a research project in which a complex computer game was designed to mimic the requirements of flight skill. It was then employed as part trainer within an actual flight training program. The game was mainly directed to teach subjects strategies of attention control and efficient allocation of processing resources. It was found to improve trainees performance in flight. The paper discusses the theoretical roots of the proposed approach and some results of its application in an actual training environment.
    Remembering Causal Systems: Effects of Systematicity and Surface Similarity in Delayed Transfer BIBA 1271-1275
      Robert M. Schumacher; Dedre Gentner
    Transfer between functionally isomorphic devices can be viewed as a kind of analogical mapping. In this research subjects learned to operate a computer-simulated device and then transferred to a functionally-equivalent device, either immediately or after a delay of one week. Two factors were varied: the systematicity, or causal coherence, of the original device mode; and the transparency, or degree of surface similarity between corresponding components in the two devices. The results showed effects of delay, systematicity and transparency. Transfer performance was better in the immediate than in the delayed condition. Both systematicity and transparency improved performance in both immediate and delayed conditions.
    Determining Transfer of Training Using Curve Fitting BIBA 1276-1279
      Diane L. Damos
    The purpose of this paper is to demonstrate the measurement of learning and transfer using a curve-fitting technique discussed in a 1985 Human Factors article by Spears. The data were collected during an experiment that determined if rotation skills could become automated with practice and if the skills could transfer between stimuli. The dependent variables of interest were the slope and intercept of the regression equation relating correct reaction time and degrees of rotation. Curve fitting was accomplished using a common statistical package, BMDP, and an IBM-XT. The curve-fitting technique showed large initial transfer of training on several variables that did not affect the asymptotic level of performance. In contrast standard transfer of training calculations indicated small positive transfer.
    Automaticity and the Transfer of Mental Rotation Skills BIBA 1280-1284
      Eric M. Grose; Diane L. Damos
    Two experiments are presented that examine automaticity and transfer of mental rotation skills. The data from these experiments were analyzed using a curve fitting technique that represents a departure from traditional methods used to analyze transfer. The first experiment demonstrated significant positive transfer from one letter stimulus to another. The second experiment examined the transfer of rotation skills from a letter to an abstract shape. Both experiments indicated mental rotation skills may become automatic with practice.

    Training: Training Potpourri

    Effects of Modes of Computer-Based Training on Learning and Retention BIBA 1285-1288
      M. Sue Bogner; Susan M. Evans
    The paper describes an investigation of the effects of computer-based training (CBT) delivery methods on learning and retention in target recognition and identification tasks. Two training methods (drill and practice, and branching computer aided instructions) were administered to subjects at two locations. Measures of cognitive complexity also were obtained on each subject and compared against test scores. Results confirmed that learning did occur with both CBT methods. Results also suggest that training design is not straightforward, and must consider a number of student and training site factors as well as the topic to be trained. Trends, while not highly significant, do suggest directions for further research.
    Conceptual Graphs as Instructional Tools BIBA 1289-1293
      Jana L. Moore; Sallie E. Gordon
    Conceptual graphs are a method of diagraming knowledge structures. They are valuable in a variety of applications including design of research. One problem has been the identification of methods for eliciting or measuring the "internal" knowledge structures to develop conceptual graphs.
       Several methods of mapping conceptual graphs have been used in various research domains (e.g., free recall, sorting, ordering, etc.). Most of these traditional methods suffer from serious drawbacks. To overcome these problems, a question probe method has been adapted from work done in the area of prose comprehension. The question probe technique is a method for systematically developing a set of "test questions". The method allows for the direct development of conceptual graphs and quantitative comparison of the graphs.
       The question probe technique has been successfully used to systematically develop instructional materials, evaluate/diagnose student understanding of course material, evaluate alternative instructional methods, and assess the relationship between instruction and problem solving performance.
    Relationship of Strength and Precision in Shooting Activities BIBA 1294-1298
      Max Vercruyssen; Robert W. Christina; Ellen Muller; Eric M. Grose
    Reported is an experiment which was designed to (1) test the strength-precision relationship of grip and shoulder strength with competitive pistol shooting scores using a nationally ranked collegiate pistol team and (2) determine the effects of a very brief, specifically focused, intense grip and shoulder strength training program (10 min, 3 times per week for 8 weeks) on strength and shooting performance. All members of the Pennsylvania State University Navy ROTC Pistol Team (n=12) were divided into two matched groups according to pre-test shooting scores. Both groups received identical shooting instruction and practice, but the training group participated in an eight-week strength development program while the control group did not. Maximum isometric strength (peak and 4-sec average force) measures were obtained from electronic output of a hand dynamometer and strain gauge (deltoid contraction from a lateral horizontal shooting position against an arm cuff). Shooting scores (slow fire, timed fire, rapid fire, and total) were used as performance measures.
    Effect of Three-Dimensional Object Type and Density in Simulated Low-Level Flight BIBA 1299-1303
      James A. Kleiss; David G. Curry; David C. Hubbard
    Three-dimensional objects placed on simulated terrain surfaces are particularly effective as cues for altitude in simulated low-level flight. To conserve the limited edge processing capacity of computer image generators (CIGs), objects have typically been simple in shape and therefore fairly abstract in appearance. The present investigation sought to determine whether the apparent size of more detailed and familiar appearing objects (e.g., trees and bushes) serves as an additional cue for altitude in simulated low-level flight. Results showed no differences in performance between abstract objects and familiar objects. However, performance did improve with increases in object density, at least for some performance measures. These results suggest that CIG processing capacity may be most effectively utilized by increasing object density rather than individual object detail.

    Training: Making Computer Conferencing Work for Army Training: From Lessons Learned to Testbed Development

    Making Computer Conferencing Work for Army Training: From Lessons Learned to Testbed Development BIBA 1304
      Robert E. Richards
    This symposium looks at the process of working through the countless conceptual and methodological issues necessary to get a new technology applied to a new setting. The papers describe the issues faced and the solutions adopted. The issues relate to applying computer conferencing to Army training but are illustrative of real-world, down-to-earth applied research. The presenters are all members of a project team that has been working with computer conferencing for over two years, full time. An overview paper points out the dangers of not questioning assumptions made early in one's learning about a new domain and the somewhat overlooked value of evaluation in the initial stages of developing a program for testing. The second paper will review the complex set of decisions made in designing, developing, and implementing a full-blown electronic classroom for the Army. The third paper describes the software that was created to meet the needs of this environment. User feedback and extensive design work went into making an intuitively simple yet surprisingly powerful interface. The fourth paper discusses the topics covered and methods used to train Army instructors for teaching in the Computer Mediated Classroom.
    Breaking Out of Conceptual/Methodological Traps: A Case Study from Research on the Computer Mediated Classroom BIBA 1305-1306
      Robert E. Richards
    This paper describes several lessons learned in the process of getting Computer Conferencing to work for Army Training. One methodological lesson was to better assess the maturity of the phenomenon to be studied and utilize formative evaluation rather than experimentation for immature areas of study. Another lesson was to not over-borrow from prevailing conceptual frameworks as they may be inappropriate for a new context. Some specifics, in case study form, are given to illustrate these lessons learned.
    Course Development for the Computer Mediated Classroom BIBA 1307-1308
      Heidi Ann Hahn
    This paper discusses considerations for designing instructional materials for the computer mediated classroom. Specifically, the topics of group versus individual instruction, information processing, media/method tradeoffs, and associated costs were addressed.
    Instructor Training for the Computer Mediated Classroom BIBA 1309-1313
      Bruce L. Kaplan; Mark K. Jones
    This paper explores the issues and dilemmas faced in designing and delivering instructor training for Army engineers to teach in a computer mediated classroom. It presents an account of the design and development and implementation processes, including the evaluation methodology and lessons. Differences between the roles of instructional staff in the computer conference and traditional school environment are also discussed.
    A User Interface for Computer Mediated Conferencing: Bridging the Gap between Needs and Expectations BIBA 1314-1315
      Bruce P. Hallbert
    As part of a computer mediated conferencing research project, a user interface was developed for the software database management programs. A process of identifying an appropriate interface is discussed as well as the factors which the researchers used to develop the interface. User needs and expectations are identified as the major factors for interface design, and methods of evaluating needs and expectations are discussed. Limitations of designing the interface to suit the particular computer conferencing course are also presented.

    Visual Performance: Visual Search and Detection

    A Threshold Model of Visual Search BIBA 1316-1319
      Daniel Workman; Donald L. Fisher
    A new model of visual search is proposed. It is suggested that in searching for a target among distractors, there is some threshold level of similarity between the target and the distractors. When the similarity of the target to a given distractor is below this threshold the distractor can be quickly rejected. When the distractor is above the threshold level of similarity it will take additional time to reject the distractor.
       Several models of visual search, including threshold and non-threshold models, are simulated on a computer and compared to the results obtained by Geiselman, Landee & Christen (1982) in a visual search task. A threshold search model in which the time to reject distractors over the similarity threshold is a function of the increment above the threshold (where similarity is defined as proposed in Workman & Fisher, 1987), is shown to provide the best fit to the data. Implications for the selection of symbols for graphic displays are briefly discussed.
    A Visual Search Model for Selection of Graphic Symbols BIBA 1320-1323
      Nancy S. Tanner; Donald L. Fisher
    Ideally one would like to select symbols for visual displays which can quickly be identified. This paper presents a model which can help select representation of an object which will speed search the most (i.e., the optimal representation) when there are several equally meaningful representations available.
    Infrared Target Detection in Structured Urban Scenes BIBA 1324-1328
      Theodore J. Doll; J. Michael Cathcart; David E. Schmieder
    An experiment was conducted to measure observers' performance in detecting military targets in structured scenes with a high density of man-made features, i.e., "urban clutter". The scenes were simulations of those produced by an infrared (IR) imaging system in air-to-ground situations. Scenes were generated with various signal-to-clutter ratios (SCR's), and were filtered to produce various levels of resolution. Detection performance was measured using a rating-scale detection task. Sensitivity (d') increased with resolution, but varied little with SCR. Contrary to expectation, detection performance for a given level of resolution and SCR was better in the present urban scenes than in rural scenes used in a previous study. The findings help define requirements for the design and employment of IR imaging systems, and also suggest directions for future research directed at better understanding target detection processes in structured backgrounds.
    A Signal Detection Paradigm for Color Display Specification BIBA 1329-1333
      Denise L. Wilson; Gilbert G. Kuperman; Eric G. Ramsey; William A. Perez
    The objective of this research was to demonstrate the validity of signal detection theory to the assessment (visual discrimination) of displayed color symbology. The area of application of the research results is in the design specification of color coded symbology to be overlayed on moving map, situational awareness displays.
       A symbol detection experiment was designed to determine how far apart, in CIE/UCS color space, symbol and background color must be in order for observers to detect that a symbol is present against the background. Six trained observers viewed a number of systematically varied symbol/background color combinations and were required to make one of six responses along a continuum from "symbol definitely present" to "symbol definitely not present".
       The analyses of the d' and Beta signal detection measures yielded different patterns of results, suggesting that this paradigm was successful in separating the cognitive and sensory/perceptual factors associated with color-on-color target detection. In addition, the shape of the Receiver Operating Characteristic (ROC) curves indicated that the assumptions underlying the signal detection paradigm were met.

    Visual Performance: Visual Display Design: Theory and Practice

    Visual Display Design: Theory and Practice BIBA 1334
      Penelope M. Sanderson
    This symposium will focus on the theory and practice of dynamic visual display design. The motivation behind it is that the sophistication of graphics hardware and software has not been matched by sophistication in the way visual information is presented, particularly in dynamic systems. The symposium participants -- Wickens, Andre, Buttigieg, Sanderson, Flach, Carswell, Woods and Elias -- will focus on how appropriate decisions are made about "what" to display, and how current theories of perception might provide practical principles on "how" to display it. They provide examples of how this has been achieved in a variety of domains.
       The problem of "what" to display is addressed by Woods and Elias in their paper on Significance Message Systems for continuous process environments. They describe and AI-based system that embodies rules for deciding what to display, given the current system context and given the types of decisions that are important in that context. This is termed the "significance of data" problem. Flach looks at the issue of what to display from an ecological perspective, arguing that task variables should be represented with respect to "critical action boundaries", or operating constraint of the system. Since dynamic systems must be described at various levels of abstraction to be properly understood, information from all levels should be displayed. The papers by Flach and by Buttigieg, Sanderson and Flach make the point that goal-relevant task invariants are what should be displayed, and provide examples of how the might be identified.
       The problem of how to display the chosen data requires solving a difficult mapping problem: making the abstract concrete. Wickens and Andre present the "compatibility of proximity" principle, which proposes that when a task requires information to be integrated, an object display will support best performance, but when focused attention is required to one aspect of the display, a non-object display such as a bar graph will do better. They show that "homogeneous" object dimensions (e.g. height and width of a rectangle) can combine to produce "emergent features", or new properties that are highly perceptually salient (rectangle area). The symposium participants agree that emergent features are a driving force behind display advantages. Flach and Buttigieg et al. argue that interactions among task variables should be represented as interactions in the visual representation: goal-relevant task invariants should be mapped into emergent properties or configural features of a display. Buttigieg et al. show that if a non-object display has goal-relevant information coded in a strong emergent feature, the non-object can actually support better performance on a task requiring integration of information than an object display.
       Many of the technical terms being used by symposium members originated in studies of visual attention, where they have precise operational definitions and existence criteria. Carswell has compared such definitions and criteria for "integrality", "configurality", etc. with current usage and finds frequent misuse of the terms. In a study of 13 bivariate graphs, she shows that true display integrality is hard to find and much of what researchers examine meet criteria for configurality only. Both she and Wickens and Andre find that the more configural they become. Configural dimensions interact perceptually to produce the emergent features that can be exploited by designers.
       The area of visual display design is benefitting from the resurrection of old theories and the development of new theories. Motivations for research in this area tend to be divided between settling theoretical issues and finding superior solutions for specific applications. The former provides a basis for generalization, but may lead to sterile parametric manipulations with little to help practitioners. The latter may lead to "straw man" display comparisons that are uninformative about the real cause of performance improvements. Wickens and Andre argue that the best approach is to pursue any research in this area with a real system in mind. Then theoretical issues might be settled in contexts that are useful to designers of visual displays. If practical visual display design is to have a sound basis, then researchers will have to translate theories into guidelines for design decisions, but equally designers will need to understand something of the theoretical and empirical foundations of these guidelines to use them effectively. We hope to promote such a dialectic in this symposium.
    Proximity Compatibility and the Object Display BIBA 1335-1339
      Christopher D. Wickens; Anthony D. Andre
    Object displays have been proposed as an efficient, economical means for presenting multiple sources of information that must be integrated. In this paper, we outline the fundamental theoretical and applied principles that have been cited to justify object display advantages, and suggest some modifications to those principles. In particular, we describe the compatibility of proximity principle which asserts that object displays will facilitate information integration, but disrupt focused attention on the individual dimensions of the object. We then discriminate between homogeneous and heterogeneous feature objects, suggesting that only the former will produce emergent features that can facilitate information integration. Finally, we describe an experiment in which the object display is designed to incorporate an emergent feature that will support the perception of aircraft stall conditions. Evaluation of the display reveals superior integration performance to a separate bar graph display, but degraded focused attention performance, thus illustrating the principle of proximity of compatibility.
    Object vs Separate Displays for Process Failure Detection: The Emergent Features Approach BIBA 1340-1344
      Mary Anne Buttigieg; Penelope M. Sanderson; John Flach
    Two studies are described that compare a "compatibility of proximity" approach to display design with an emergent features approach. Results suggest that tasks requiring integration are not necessarily better supported by an integral or object display than a separated display. A bar graph with a strong emergent feature mapped onto a goal-relevant task invariant supported better integrated task performance than a triangle display that in previous research had shown superiority when compared with weaker bar graph displays. Further research in progress is outlined. Our findings suggest that an emergent features approach to display design might be a more encompassing approach than one based solely on compatibility of proximity.
    Integral, Configural, and Unitary Graphs BIBA 1345-1349
      C. Melody Carswell
    Thirteen graphical formats, each designed to display two variables, were subjected to performance-based diagnostics of integrality, configurality, and perceptual unity. None of the graphs appeared to be composed of integral dimensions; however, several graphs were classified as unitary or configural. When graphical elements or dimensions were combined into a single object, they tended to be associated with the unitary pattern of performance. Homogeneous object displays tended to be associated with configural outcomes.
    Significance Messages: An Integrated Display Concept BIBA 1350-1354
      David D. Woods; Glenn Elias
    This paper describes one integral display concept -- Significance Messages -- which communicates the significance of a numerical value of some continuous parameter. The Significance Messages System combines a variety of kinds of raw data using software techniques from artificial intelligence in order to build a qualitative scale that communicates what a numeric value of some parameter means about the state of the application world given the current context. The Significance Messages concept is built as a generic "shell" that knows about different kinds of qualitative states, contextual factors, and heuristics to focus on relevant data. The designer enters domain specific, parameter specific knowledge about alarm setpoints, automatic system setpoints, etc. and about the specific contextual factors that are relevant to the interpretation of that parameter in order to create a particular Significance Messages Display for a particular application.
    Direct Manipulation, Direct Engagement, and Direct Perception: What's Directing What? BIBA 1355-1358
      John M. Flach
    The term "direct" has been used quite liberally in recent discussions of human performance and human-machine systems. Shneiderman (1983) discusses "direct manipulation"; Hutchins, Hollan and Norman (1986) discuss "direct engagement"; and Gibson (1979) "discusses" "direct perception". This paper will compare these different uses of the term "direct" and will examine the implications for interface design.

    Visual Performance: Panel

    Perspective Displays: The Control of Motion in 3-D Virtual Space BIBA 1359-1360
      C. T. Bennett; W. W. Johnson; M. L. Braunstein; J. M. Flach; L. Wolpert
    Perspective displays have been used to better understand how people perceive self translation and rotation. Much of the early work in this are was conducted with cinematic displays and a passive observer. More recently, making use of lower cost, high speed graphics oriented computers, investigators have studied the interactive regulation of perspective scenes. The study of the active control of optical flow has both challenged some early hypotheses, and provided some insight into the impact that methodology has on the perception of perspective displays.
       The use of perspective displays has also expanded with the opportunity for people to work in 3-D virtual environments. Examples of such environments include work stations in the space shuttle, or indeed any hostile environment where the operator is remote from the viewing plane of a sensor. Such teleoperation has placed a burden on designers of such work stations to understand both the mathematical principles that underlay perspective, as well as the perceptual sensitivity to optical variables.
       The panel members will discuss the recent developments in the study of optical flow as it relates to the perception of computer generated virtual worlds, and the analytical and methodological techniques involved in the study of perspective displays. But, emphasis will be placed on optical flow and the perception/control of motion while observing perspective displays.
       The empirical and computational study of optical flow has led to a more complete understanding of the visual information used to control self motion. The term optical flow refers to the relative motion of surface texture elements during angular and/or translational transformation of an observer. Although the mathematical transformation of an entire image is computationally intense, the actual calculation of the movement of texture elements is not difficult. It is based on only three variables: slant angle, slant range, and velocity. Slant angle incorporates both azimuth and elevation of a surface point from the observer. Slant range is the actual line of sight distance between the observer and the texture element. Velocity, of course, incorporates both the speed and the direction of translation or rotation of the observer.
       It is important to remember that the term optical flow makes reference to the geometric relationship of surface points to an observer, and how that relationship changes as the observer moves. In using the term optical flow, it is not assumed that the observer can or does make appropriate use of the optical information. Optical flow merely makes reference to the physical stimuli. The term visual flow refers to those elements in the optical flow that are supra-threshold.
       Perspective displays are typically based on the graphical representation of a surface. At a minimum, these displays incorporate the density and compression gradients that describe the plane. Density is defined as the frequency of surface elements within a given viewing angle. Compression refers to the apparent decrease in distance between surface elements as distance from the observer increases.
       If we are to describe and quantify how a human operator uses a perspective display, we must be careful how we operationally define the very basic concepts discussed above. How such concepts have been quantified will serve as the central theme of the discussions.

    Visual Performance: Information Portrayal Determinants of Complex Decision Making

    The Bargraph as a Configural and a Separable Display BIBA 1361-1365
      Bruce G. Coury; Janine Purcell
    The results from two experiments demonstrate the conditions under which a bargraph display can be processed both as a configural display and as a separable display. When there is a unique mapping of display attributes to system state categories (Experiment 1), the perceptual cues in the bargraph display serve to produce superior classification performance. Once that mapping and predictability is disrupted (Experiment 2), operators resort to analyzing the bargraph display in a separable fashion and produce performance equivalent to the serially processed digital display. Uncertainty (i.e., the degree to which a value or set of values of process variables map to a single system state) appears to be the primary factor affecting the way in which the bargraph display will be processed.
    Asymmetric Transfer of Training Between Integral and Separable Displays BIBA 1366-1370
      Janine A. Purcell; Bruce G. Coury
    The type of display employed during operator training may affect the formation of an operator's internal model of the system. In this experiment, subjects were divided into two groups and trained to classify instances of system state using either a configural or digital display. During extended practice the subjects were then switched to the alternate display type; those trained on the configural display now worked with the digital display, and vice verse. Results indicate that asymmetric transfer of training occurred; those who switched from the digital to the configural display outperformed the other group by a significant margin in term of accuracy. Results are discussed in terms of the impact of display type on the formation of the operator's internal model and bias of processing strategy in transfer situations.
    The Interaction of Spatial and Color Proximity in Aircraft Stability Information Displays BIBA 1371-1375
      Anthony D. Andre; Christopher D. Wickens
    The objective of a complex display design is to provide information in a way that maximizes the user's ability to process that information. This paper explores the effects of manipulating the spatial and color proximity among the information displays relevant to aircraft stability during both integration and focused attention tasks. The principle of compatibility of proximity (Wickens, 1987) suggests that tasks requiring the operator to integrate multiple sources of information are better served by close display proximity while tasks that require focused attention on specific sources of information are better served by more separate displays. Color proximity results clearly supported this principle and showed that using a common color (i.e. close proximity) to code different information sources facilitated integration performance while using separate colors to code different information sources facilitated focused attention performance. However, close spatial proximity did not foster integration. Instead, distant spatial proximity yielded superior performance for both focused attention and integration tasks.
    Modeling Information Search Behavior for Design Purposes: An Example from Process Control BIBA 1376-1380
      Gunilla A. Sundstrom
    Current model son operator behavior in supervisory control systems are reviewed with special focus on their usefulness for graphical design of human-machine interfaces in dynamic technical systems. An alternative framework is described and used in a knowledge based approach to represent information search behavior of operators for graphical design purposes.

    Visual Performance: Computer Displays

    Standardizing Colors for Computer Screens BIBA 1381-1385
      Wanda Smith
    The increase and excessive use of inappropriate and inconsistent colors on computer display images has necessitated the development of standards for their color specification. A description is given of the color standard draft proposal developed for ISO (International Organization for Standardization). The draft includes specifications for color values to ensure color perception and interpretation and an Annex of non-normative guidelines.
    Effects of Display Failures and Symbol Rotation on Visual Search Using Dot-Matrix Symbols BIBA 1386-1390
      Jennie J. Decker; Craig J. Dye; Ko Kurokawa; Charles J. C. Lloyd
    This study was conducted tin investigate the effects of display failures and rotation of dot-matrix symbols on visual search performance. The type of display failure (cell, horizontal line, vertical line), failure mode (ON, failures matched the symbols; OFF, failures matched the background), percentage of failures (0, 1, 2, 3, 4%), and rotation angle (0, 70, 105 degrees) were the variables examined. Results showed that displays which exhibit ON cell failures greater than 1% significantly affect search time performance. Cell failures degrade performance more than line failures. Search time and accuracy were best when symbols were oriented upright. The effects of display failures and rotation angle were found to be independent. Implications for display design and suggestions for quantifying the distortion due to rotation are discussed.
    The Effects of Image Rotation on Dot-Matrix Characters BIBA 1391-1394
      Ko Kurokawa; Jennie J. Decker; Patti L. Kelly; Harry L. Synder
    This study investigated how rotation of dot-matrix characters influenced human performance, measured by the response time in a random search task. Factors that influence the extent of dot-matrix pattern distortion were identified, and their effects were investigated. Significant effects were found in angle of rotation (p=0.0046; 0 to 180 degrees in a 5-degree increment), target character's distance from the center of rotation (p<0.0001), and target characters (p<0.0001). Issues pertinent in predicting the effect of dot-matrix pattern distortion on performance are discussed.
    Rapid Communication Display Technology Efficiency in a Multi-Task Environment BIBA 1395-1399
      Sarah Swierenga Osgood; Kenneth R. Boff; Rebecca S. Donovan
    The present study examined the advantage of Rapid Communication (RAP-COM) Display Technology over conventional spatially arrayed displays in the context of secondary task demands. This research represents an early step in assessing the use of RAP-COM display techniques in multi-task environments. Eight subjects were instructed to respond to briefly presented visual stimuli, while concurrently performing an unstable tracking task at two levels of difficulty. Duration thresholds, obtained using a moment-to-moment adaptive tracking performance procedure, were collected for RAP-COM and spatially arrayed displays while RMS error scores were collected from the unstable tracking task performance. Information transfer rates for the RAP-COM technique were faster than for the spatially distributed array under both the single and dual task conditions. Regardless of secondary tracking task difficulty, subjects were able to maintain primary task performance levels on RAP-COM and spatial display tasks, although a decrement in tracking performance was seen.

    Visual Performance: Physiological and Subjective Assessment of Workload

    Using Probe Evoked Potentials to Determine Information Processing Demands BIBA 1400-1403
      Glenn F. Wilson; Kathy McCloskey
    In the present study, three different types of probe evoked potential (EP) techniques were examined using a mental math task with three levels of difficulty. One probe condition consisted of presenting flashes at 5 sec intervals during the performance of each task level. The other conditions were designed such that probe flashes were presented at 250 and 750 msec after the onset of each mental math task item. Baseline (no task) measurements were taken for all three probe conditions. Subjects were 6 males and 4 females who participated in an earlier study (Yolton, Wilson, Davis and McCloskey, 1987), and were recalled for the present experiment. Results of the RT data replicated those found in Yolton, et al (1987), where RT increased as task level increased. The EPs obtained from each of the probe conditions showed different patterns of variation with task demand. The 5 sec probe showed differences between the no-task baseline and all other levels of the task, but not between task levels. The 250 msec probe EPs showed graded changes with task level, whereas the 750 msec probe EPs were similar to those found with the 5 sec probe EPs. These measures support the notion that probe EPs are not only measures of tonic activity, but are also measures of phasic activity. To index phasic activity, probes must be present during relevant times during task performance. The usefulness of this technique is discussed in terms of moment-to-moment fluctuations of processing demands in applied situations.
    Mental Workload and P300 Component of Event-Related Brain Potentials in a Visual Monitoring Task BIBA 1404-1408
      Hamo Lalehzarian
    The attributes of event-related brain potentials (ERPs) when combined with the information gained from the study of apparent human behavior, can provide valuable information about central nervous system processes. This study illustrates the manner in which these attributes, specifically P300 amplitude, can be used to study human information processing. This research investigated the effects of a systematic increase in mental workload, and the position of the stimulus on the P300 amplitude. The task chosen was a visual monitoring task with four levels of increased task difficulty. A slight increase in the P300 amplitude was observed from level 1 to level 2. At level 3, a significant increase in the amplitude of P300 component was observed from level 2. At level four, no major increase in the P300 amplitude was observed from level 3. At any task difficulty level, the P300 amplitudes were not affected by the position of the monitored cell. Infrequent large changes in the readout value of the monitored cells elicited larger P300 amplitudes than frequent small changes.
    The Effects of Biodynamic Stress on Workload in Human Operators BIBA 1409-1413
      William B. Albery; Merry M. Roe; Charles D. Goodyear; Kathy A. McCloskey
    The objective of this research was to assess the effects of two biodynamic stressors, noise and acceleration, commonly experienced in the aircraft cockpit, on human operator performance and workload. Thirteen workload measures, including one subjective, four performance and eight physiological, were recorded on subjects performing a dual psychomotor task. The results indicate that biodynamic stressors such as noise and acceleration can adversely affect subjective operator workload without affecting objective task performance.
    Critical SWAT Values for Predicting Operator Overload BIBA 1414-1418
      Gary B. Reid; Herbert A. Colle
    The Subjective Workload Assessment Technique (SWAT) has been used to assess mental workload in a variety of situations. As with subjective techniques generally, use of SWAT has emphasized relative comparisons of task conditions. For example, it has been possible to determine if one task or display required a greater mental workload than another. For many applications, however, it would be useful to have identified a critical SWAT level that indicates likely performance degradation caused by operator overload. A review of previously completed studied suggests a range of SWAT scores that were predictive of operator overload.

    Visual Performance: Advanced Displays I

    Video Image Presentation Methods for High-Speed Mail Piece Encoding BIBA 1419-1423
      Christopher G. Koch; Ginny Ju
    A program of research was conducted to determine the design requirements for a prototype image processing system to provide high-resolution video images of mail pieces -- irregular parcels and pieces, flats, and letters -- and enable high-speed data entry of coding information by operators. Experiments were performed to determine effective image transition methods, pacing strategies, and image preview methods for entering numerals from ZIP Codes of mail piece addresses on a 10-key keyboard. Results showed performance advantages of response speed, throughput, and fewer misses for fade-out transition between images, combined operator and machine pacing, and image preview by early transition to the next image in queue.
    Latencies of the Eye and Head to Targets in the Vertical and Horizontal Planes BIBA 1424-1428
      William P. Janson; Gloria L. Calhoun
    Past studies involving oculomotor responses have typically been limited to refixations along the horizontal plane, small samples sizes, and little data pertaining to head movement. The study reported herein addresses these data voids by collecting both eye and head latency data for refixations in the horizontal and vertical planes. The subjects' task was to perform a central manual tracking task while periodically responding to a verbal command to classify a target on one of four peripheral monitors. Two targets were displayed along the horizontal plane and two along the vertical plane. Results from 620 trials indicated similar trends for the eye and head latency across all four monitor locations, suggesting no significant differences in eye or head latency as a function of target plane.
    Using Target Replacement Performance to Measure Spatial Awareness in a Helmet-Mounted Simulator BIBA 1429-1433
      Maxwell J. Wells; Michael Venturino; Robert K. Osgood
    Measurements were made of the ability of 20 subjects to acquire 3,6 or 9 stationary visual targets and then replace them after they had been removed. The targets were viewed with various sized fields-of-view (FOVs) using a Visually Coupled Airborne Systems Simulator (VCASS), which was mounted on the head and which used head position information to provide space-stabilized computer-generated images. Targets were presented with a blank background or a terrain background. Subjects were instructed to use as much time as they required or to be as quick as possible searching for the targets. Mean times to search for the targets were faster with the larger FOVs and faster with fewer targets. Replacement accuracy was not sensitive to the FOV but decreased with increasing number of targets. Search times were slower, but replacement accuracy was greater with a terrain background than with a bland background. In the fast search conditions, the number of guessed target replacements decreased with decreasing numbers of targets and increasing FOV. It is concluded that target replacement performance was sensitive to manipulation of the independent variables and as such is a potentially useful metric of spatial awareness.
    Perceived Change in Orientation from Optic Flow in the Central Visual Field BIBA 1434-1438
      Brian P. Dyre; George J. Andersen
    An important consideration for some types of flight simulation is that sufficient information be provided for a vertical perception of a pilot's motion and/or change in orientation. Previous research (Andersen & Braunstein, 1985) has suggested that induced self-motion from stimulation of the central visual field may be related to internal depth within the display. The purpose of the present study was to examine the effects of internal depth within the display on perceived changes in orientation. Subjects monocularly viewed displays simulating observer motion within a volume of randomly positioned points through a window which limited the field of view to 15 degrees. The velocity of the displays varied according to a sum of four frequencies. Change in posture was used to measure changes in perceived spatial orientation. Three variables were examined: 1) the extent of internal depth within the display, 2) the presence of absence of visual information specifying change in orientation, and 3) the frequency of motion simulated by the display. A frequency analysis of postural sway indicated that increased sway occurred at frequencies of .375 Hz and lower when motion at these frequencies was present in the display. However, the extent of internal depth in the display had no consistent effect on the perception of changing orientation. The implication of this research for flight simulation will be discussed.

    Visual Performance: Advanced Displays II

    Relationship of Static Stereoscopic Depth Perception to Performance with Dynamic Stereoscopic Displays BIBA 1439-1442
      James S. Tittle; Michael W. Rouse; Myron L. Braunstein
    Although most tasks performed by human observers that require accurate stereoscopic depth perception, such as working with tools, operating machinery, and controlling vehicles, involve dynamically changing disparities, classification of observers as having normal or deficient stereoscopic vision is currently based on performance with static stereoscopic displays. The present study compares the performance of subjects classified as deficient in static stereoscopic vision to a control group with normal stereoscopic vision in two experiments -- one in which the disparities were constant during motion and one in which in the disparities changed continuously. In the first experiment, subjects judged orientation in depth of a dihedral angle, with the apex pointed toward or away from them. The angle translated horizontally, leaving the disparities constant. When disparity and motion parallax were placed in conflict, subjects in the normal group almost always responded in accordance with disparity, where as subjects in the deficient group responded in accordance with disparity at chance levels. In the second experiment, subjects were asked to judge the direction of rotation of a computer-generated cylinder. When dynamic occlusion and dynamic disparity indicated conflicting directions, performance of subjects in the normal and deficient groups did not differ significantly. When only dynamic disparity information was provided, most subjects classified as stereo deficient were able to judge the direction of rotation accurately. These results indicate that measures of stereoscopic vision do not include changing disparities may not provide a complete evaluation of the ability of a human observer to perceive depth on the basis of disparity.
    Vertical Disparity in Advanced Automotive Displays BIBA 1443-1447
      Maurice S. Schaeffer; John L. Campbell
    The optical systems being considered for automotive virtual image displays may confront drivers with significantly more vertical disparity than their military counterparts. Military head-up displays, for example, are limited to 1 milliradian (mrad) of vertical disparity whereas automotive displays may have 5 mrad.
       Three experiments were performed to examine performance with virtual image displays as a function of amount of vertical disparity. Stimuli were simple speedometer dials with embedded tripmeters representing both analog and digital display tasks. Stimuli were presented tachistoscopically and subjects were required to read one or both instruments on each trial.
       Disparity did not affect performance accuracy. Large disparities did, however, results in diplopia and, possibly suppression of one of the visual images. Nevertheless, it appears that, at least in the driving situation, where displays are used intermittently and briefly for the information contained in them, comparatively large amounts of vertical disparity in displays will not degrade performance and may not be noticed.
    Human Factors Issues Associated with In-Car Navigation System Usage (An Overview of Two In-Car Experimental Studies) BIBA 1448-1452
      Thomas A. Dingus; Jonathan F. Antin; Melissa C. Hulse; Walter W. Wierwille
    Two research studies were recently performed to evaluate and test human factors aspects of a commercially available in-car navigation system. The first study addressed the driver visual attentional demand requirements of the system and its effects on driving performance and behavior. The second study addressed the effectiveness of the system as a navigation tool as well as methodological aspects of navigation. The results of the first study indicate that several tasks performed during navigation required high visual attentional demand. Design changes are discussed which would likely reduce this demand. The results of the second study indicate that drivers are able to navigate effectively using the device. However, results also show that scan patterns are changed when the device is in-use.
    Distance and Clearance Perception Using Forward-Looking, Vehicular Television Systems BIBA 1453-1457
      Dwight P. Miller
    During off-road navigation, drivers often must make size, distance, and clearance judgments of terrain features and obstacles in order to choose safe navigational routes. These same judgments must be made in teleoperation of land vehicles using forward-looking television systems. This study evaluated how well subjects perceived size, distance, and clearance using monochrome and color television systems. Thirty-eight subjects (Ss) estimated the size, distance, and separation of two obstacles using video imagery produced by a forward-looking, vehicle-mounted camera. Results indicate that Ss typically overestimated distances, and when in error judging clearance, tended to overestimate the gap between the objects. These biases were expected due to the well documented minification effect of television using standard lenses. More surprising was the somewhat larger bias evidenced by Ss using color versus those using monochrome imagery. This paper will describe the research methodology, the results obtained, potential reasons for the results, discuss the plans for continuing research in this area, and assess the implications these findings may have on teleoperated vehicle design.

    Visual Performance: Time-Sharing, Vigilance, and Behavioral Assessment of Workload

    Effects of Task Demands and Age on Vigilance and Subjective Workload BIBA 1458-1462
      John E. Deaton; Raja Parasuraman
    Sensory and cognitive vigilance were directly compared in two experiments. The question of whether sensory and cognitive vigilance task demands can be differentiated on the basis of perceived workload was also addressed. A third focus of the study was to investigate changes in sensory and cognitive vigilance across the adult life span. In Experiment 1 60 subjects from three age categories -- young, middle, and elderly were studied. Experiment 2 consisted of 20 subjects from only the young and old age categories. Subjects performed a visual sensory and a cognitive vigilance task at low and high event rates. Each task used identical stimulus sets (pairs of digits) and differed only in the definition of a critical target. Task demands were a major determinant of vigilance performance. Cognitive vigilance was more resistant to decrement over time than sensory vigilance. On the other hand, the cognitive task was more adversely affected by high event rate than the cognitive task, particularly at the high event rate. Subjective workload results suggested that the increased mental demands required of the cognitive task at the high event rate were associated with performance differences between sensory and cognitive tasks. However, the results also revealed an apparent dissociation between performance and subjective workload measures. Implications of the results for display design and assessment of individual differences in monitoring capability are discussed.
    Capacity Demand in Dual-Task Monitoring of Simultaneous and Successive Vigilance Tasks BIBA 1463-1465
      Jonathan P. Gluckman; William N. Dember; Joel S. Warm
    Parasuraman and Davies (1977) have proposed a taxonomic analysis of vigilance performance which emphasizes the types of discriminations observers are required to make and the information-processing demands placed upon them. According to Parasuraman and Davies, successive (absolute judgement) tasks are more capacity-demanding than simultaneous (comparative judgement) tasks because they invoke working memory. This idea has received support from several investigations demonstrating that psychophysical factors which degrade vigilance performance have more of a negative impact upon successive than upon simultaneous tasks (see Parasuraman, Warm and Dember, 1987 for review). The present study examined the capacity-demand notion further by determining the effects that the two types of tasks have upon one another when they are both performed in a common vigilance session. By doing so, it provides the initial experimental effort to investigate the task dimension of the taxonomy within the context of a previously unexplored aspect of Parasuraman and Davies' classification system, source complexity.
    Flexibility in Resource Allocation and the Performance of Time-Sharing Tasks BIBA 1466-1470
      Gabriel Spitz
    The extent and nature of the ability to control the allocation of mental resources between the components of a dual task was investigated in three separate experiments. Using a variable priority (demand) methodology it was found that subjects could manipulate their performance level, however their ability to meet specific demand levels was limited. Training subjects under single or dual-task conditions using a wide range of task demand significantly improved dual task performance and degree of control over resource allocation as compared to performance following practice under a narrow range of task demands or under single task fixed demand conditions. Single task performance among all groups improved to the same degree. It was concluded that training subjects under a wide range of task demands increases the range of performance levels over which mental resources can be flexibly allocated for those tasks and improves time sharing performance. Implications for the design of training for complex task performance are discussed.
    A Dissociation of Objective and Subjective Workload Measures in Assessing the Impact of Speech Controls in Advanced Helicopters BIBA 1471-1475
      Michael A. Vidulich; Michael R. Bortolussi
    Among the new technologies that are expected to aid helicopter designers are speech controls. Proponents suggest that speech controls could reduce the potential for manual control overloads and improve time-sharing performance in environments that have heavy demands for manual control. This was tested in a simulation of an advanced single-pilot, scout/attack helicopter. Objective performance indicated that the speech controls were effective in decreasing the interference of discrete responses during moments of heavy flight control activity. However, subjective ratings indicated that the use of speech controls required extra effort to speak precisely and to attend to feedback. Although the operational reliability of speech controls must be improved, the present results indicate that reliable speech controls could enhance the time-sharing efficiency of helicopter pilots. Furthermore, the results demonstrated the importance of using multiple assessment techniques to completely assess a task. Neither the objective nor the subjective measures alone provided complete information. It was the contrast between that was most informative.