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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 34th Annual Meeting 1990-10-08

Fullname:Proceedings of the Human Factors Society 34th Annual Meeting
Note:Countdown to the 21st Century
Location:Orlando, Florida
Dates:1990-Oct-08 to 1990-Oct-12
Standard No:ISSN 0163-5182; TA 166 H794; hcibib: HFS90-1
Links:Online Proceedings
  1. HFS 1990-10-08 Volume 1
    1. Aerospace Systems: Displays and Controls
    2. Aerospace Systems: Panel
    3. Aerospace Systems: Situational Awareness
    4. Aerospace Systems: Decision Aids and Performance
    5. Aerospace Systems: Workload I
    6. Aerospace Systems: Panel
    7. Aerospace Systems: Displays, Maps, and Color Coding
    8. Aerospace Systems: Workload II
    9. Aerospace Systems: Human Factors of Teleoperation in Space
    10. Aging: Aging and Everyday Activities
    11. Aging: Age-Related Slowing of Performance
    12. Aging: Aging Potpourri
    13. Communications: The Design of Communication Systems I: The Use of Voice
    14. Communications: The Design of Communication Systems II: Keypads and Icons
    15. Communications: Panel
    16. Communications: The Design of Communication Systems III: Teaching and Training
    17. Computer Systems: Modeling
    18. Computer Systems: Panel
    19. Computer Systems: Interface Design Issues
    20. Computer Systems: Prototyping/Usability
    21. Computer Systems: Panel
    22. Computer Systems: Knowledge Acquisition/Expert Systems
    23. Computer Systems: Quantifying Interface Design
    24. Computer Systems: Analyzing, Designing, Developing, and Evaluating Adaptive Systems
    25. Computer Systems: Interfacing with the User
    26. Computer Systems: Input Devices
    27. Computer Systems: Panel
    28. Computer Systems: Human-Computer Interaction
    29. Computer Systems: Head Movement, Gestures, and Speech Input
    30. Computer Systems: Information Presentation
    31. Consumer Products: Design Methods and Guidelines
    32. Consumer Products: Basic Design: Controls and Displays
    33. Consumer Products: Human Factors in Consumer Products
    34. Consumer Products: Panel
    35. Consumer Products: Symbols
    36. Consumer Products: Warnings!
    37. Educators' Professional: Panel
    38. Educators' Professional: Methods and Evaluation of Human Factors Instruction
    39. Environmental Design: Environmental Design Interventions
    40. Environmental Design: Invited Address
    41. Environmental Design: Noise, Doors, Spaces, and Floors
    42. Forensics Professional: Warnings and Automobile Safety
    43. General Sessions: Panel
    44. General Sessions: Potpourri
    45. General Sessions: Panel
    46. General Sessions: Human Factors in Automotive and Transportation Applications
    47. General Sessions: Methods and Techniques Potpourri
    48. General Sessions: Panel
    49. General Sessions: Potpourri II
    50. Industrial Ergonomics: Lower Back Biomechanics
    51. Industrial Ergonomics: Manual Material Handling I
    52. Industrial Ergonomics: Case Studies in Ergonomics
    53. Industrial Ergonomics: Industrial Ergonomics Potpourri
    54. Industrial Ergonomics: Workstation Design
    55. Industrial Ergonomics: Manual Material Handling II
    56. Industrial Ergonomics: Human Force Exertion
    57. Industrial Ergonomics: CTS and Hand-Wrist Biomechanics

HFS 1990-10-08 Volume 1

Aerospace Systems: Displays and Controls

Eye and Head Response as Indicators of Attention Cue Effectiveness BIBA 1-5
  Gloria L. Calhoun; William P. Janson
This study examined whether eye and head responses can be used to evaluate attention cue effectiveness. The subjects' tasks were to complete a centrally-located tracking task while periodically responding to cues to identify targets at four peripheral locations. Five directional cues were evaluated: visual symbol, coded sound, speech cue, three dimensional (3-D) sound and 3-D speech (the 3-D cues appeared to emanate from the peripheral locations). The results showed significant performance differences in eye and head reaction time, as well as peripheral target task completion time, as a function of cue modality. Since these relatively nonobtrusive measures were as sensitive to cue modality as the peripheral task completion time, these results suggest that eye and head reaction time can be used in evaluations addressing the effectiveness of attention cues.
Evaluation of a Directional Audio Display Synthesizer BIBA 6-10
  German Valencia; Jeffrey R. Agnew
A three-dimensional (3-D) auditory display imposes directionality to audio signals, over headphones, so that they are perceived as originating from unique spatial locations outside the listener's head. This study evaluated subjects' localization performance with a Directional Auditory Display (DIRAD) synthesizer. Subjects' ability to perceive the direction of target sounds in the azimuth plane was measured as a function of head movement with four types of audio stimuli. Results showed significant localization performance differences as a function of sound location, head movement condition and stimulus type. These results help to define the functional requirements of a 3-D auditory display prior to the integration of synthesized directional audio into flight simulators and advanced aircrew systems.
Icons vs. Alphanumerics in Pilot-Vehicle Interfaces BIBA 11-15
  Monica J. Camacho; Bruce A. Steiner; Barry L. Berson
The effects on performance from the use of icons and alphanumerics in pilot-vehicle interfaces were investigated in an experiment. Varying numbers of single status display indicators were presented in both iconic and alphanumeric formats in fixed and random display positions across three levels of difficulty. Subjects' ability to maintain a tracking task while concurrently searching and selecting appropriate display indicators was tested. Results indicated that for all numbers of indicators presented, icons produced faster search and selection reaction times. Significant interactions were also found for format type and difficulty level. Questionnaire assessment revealed that subjects preferred the iconic to the alphanumeric formats. Implications for the design of aircraft interfaces and further research suggestions are discussed.
The Relative Effectiveness of Three Visual Depth Cues in a Dynamic Air Situation Display BIBA 16-20
  Kim M. Mazur; John M. Reising
The purpose of this study was to evaluate the effectiveness of three visual depth cues, and combinations of these cues, in a dynamic air situation display. The study was conducted to help determine how best to display aircraft location to a pilot. Three different depth cues (stereo 3-D, aerial perspective, and familiar object size), were investigated. Additionally, two levels of display density (13 or 25 aircraft) were evaluated. The results of the study indicated that the number of depth cues, which ranged from zero to three, affected the subject's ability to determine aircraft location. Display density also affected performance. However, the particular type of depth cue did not have a differential effect. In other words, it makes a difference if one or two depth cues are displayed, but not the particular cues used.

Aerospace Systems: Panel

Situational Awareness in the Advanced Commercial Aircraft Cockpit BIB- 21-25
  Nadine B. Sarter; David D. Woods; Rolf J. Braune; Everett Palmer; William H. Rogers; Christopher D. Wickens; Kelly Harwood; Anthony Andre; Anthony Aretz; Earl L. Wiener; Elmar Boje

Aerospace Systems: Situational Awareness

Cognitive Quality and Situational Awareness with Advanced Aircraft Attitude Displays BIB- 26-30
  R. M. Taylor; S. J. Selcon
An Evaluation of the Augie Arrow HUD Symbology as an Aid to Recovery from Unusual Attitudes BIB- 31-35
  John E. Deaton; Michael Barnes; Jonathan Kern; Douglas Wright
The Use of 3-D Stereo Display of Tactical Information BIBA 36-40
  Bruce A. Steiner; Diane A. Dotson
This study examined the effects of adding 3-D stereoscopic altitude information to a standard aircraft tactical situation display. In an experiment, displays presenting varying number of hostile aircraft were presented to subjects in either a 2-D or 3-D format via a computer driven real time simulation system. Tests indicate, that for all levels of number of threats, the 2-D displays resulted in faster response times and fewer errors to locate particular classes of targets. Questionnaire and interview results, however, showed that subjects prefer the use of 3-D displays, and felt that their use gave them a competitive edge over their opponents. Implication for the use of this technology in aircraft heads down displays, as well as suggestions for further research are discussed.
Predictive Utility of an Objective Measure of Situation Awareness BIB- 41-45
  Mica R. Endsley

Aerospace Systems: Decision Aids and Performance

Decision Support in the Cockpit: Probably a Good Thing? BIB- 46-50
  Stephen J. Selcon
When is a Naval Outer Air Battle Like a Nuclear Power Plant? BIB- 51-55
  William F. Stubler
Targeting Decisions Using Multiple Imaging Sensors: Operator Performance and Calibration BIB- 56-60
  Scott A. Weisgerber; Marion P. Kibbe
The Effects of Scene Complexity on Judgements of Aimpoint During Final Approach BIB- 61-65
  Woodrow Barfield; Craig Rosenberg

Aerospace Systems: Workload I

TASKILLAN II: Pilot Strategies for Workload Management BIB- 66-70
  Leon D. Segal; Christopher D. Wickens
Planning and Scheduling in Flight Workload Management BIB- 71-75
  Mireille Raby; Christopher D. Wickens
Mental Models, Mental Workload, and Instrument Scanning in Flight BIB- 76-80
  Donald E. Hameluck
An Initial Test of a Normative Figure of Merit for the Quality of Overall Task Performance BIB- 81-85
  Moira LeMay; J. Raymond, Jr. Comstock

Aerospace Systems: Panel

Pilot-Vehicle Interface -- Advanced Concepts BIB 86-88
  Carol Lynn Judge; John Hammer; Robert M. Yadrick; Andrew A. Hollenbeck; Guy E. Clayton; Victor Riley; Everett Palmer; T. S. Abbott; Ronald L. Small

Aerospace Systems: Displays, Maps, and Color Coding

Map Display Design BIBA 89-93
  Anthony J. Aretz
This paper presents a cognitive model of a pilot's navigation task and describes an experiment comparing a visual momentum map display to the traditional track-up and north-up approaches. The data show the advantage to a track-up map is its congruence with the ego-centered forward view; however, the development of survey knowledge is hindered by the inconsistency of the rotating display. The stable alignment of a north-up map aids the acquisition of survey knowledge, but there is a cost associated with the mental rotation of the display to a track-up alignment for ego-centered tasks. The results also show that visual momentum can be used to reduce the mental rotation costs of a north-up display.
Airborne Early Warning and Color-Coding BIBA 94-98
  G. L. Ricard
This study examined improvements to airborne early warning possible by color-coding information into the current surveillance radar system of the E-2C aircraft. It used man-in-the-loop simulation to examine performance in a taxing but realistic, war-alert scenario, and a number of measures of operator performance were taken that showed differences between color and monochrome operation. A set of nine functions was selected for color-coding, and a scheme was developed to code their information into colors for the operator's main display. Both operational Navy and Grumman E-2C operators were tested under color and monochrome conditions and the results strongly favor operation with color. Operators remained more aware of the tactical situation, organized better defenses of their task force, and reduced threats to the fleet better with the color-coded display. Non-redundant color-coding should be considered for any complex tactical task where performance can be expected to improve if more information is displayed -- particularly in cases where operators' manipulation of controls can be reduced and their decision making can be made less dependent on memory.
Color Coding and Size Enhancements of Switch Symbol Critical Features BIBA 99-103
  Kristen K. Barthelemy; Kim M. Mazur; John M. Reising
The purpose of these two studies was to evaluate recognition performance of symbols on programmable switches using different critical feature enhancement techniques. Based on previous studies, it was assumed that subjects were processing the meaning of the symbols at a holistic level. Enhancing a critical feature (the specific part of a symbol which makes it most identifiable) was proposed as a method for creating a more unique symbol, thereby improving recognition performance. Color coding and size enhancement of the critical feature were evaluated to determine if either technique improved symbol recognition performance. In the first study the size enhancement was between 60-75% in total number of pixels for the critical feature. The amount of size enhancement was limited by the display surface area. In the second study, a new method of size enhancement was utilized whereby the longest axis of the critical feature was increased by 0.10 of an inch. In this study, there was no display surface constraint. In both studies color coding of the critical feature was also evaluated. The results of the first study indicated that only the color coding technique was significant. In the second study, both color coding and size enhancement were significant. It was concluded that in the first study the way in which the size enhancement was applied to the critical feature (an increase in total surface area) was not sufficient to achieve a unique symbol, so it did not improve the subject's recognition ability; however, in the second study, size enhancing the longest axis was sufficient to result in a performance payoff.

Aerospace Systems: Workload II

A Secondary Analysis Comparing Subjective Workload Assessments with U.S. Army Aircrew Training Manual Ratings of Pilot Performance BIB- 104-108
  John E., II Stewart; Ronald J. Lofaro
Classification of Flight Segment Using Pilot and WSO Physiological Data BIB- 109-111
  Glenn F. Wilson; Frank Fisher
A Validation of SWAT as a Measure of Workload Induced by Changes in Operator Capacity BIB- 112-115
  Jonathan M. Hankey; Thomas A. Dingus

Aerospace Systems: Human Factors of Teleoperation in Space

Human Factors of Teleoperation in Space BIB 116-120
  Thomas J. Smith; Mark A. Stuart
Hand Controller Commonality Evaluation Process BIB- 121-125
  Mark A. Stuart; Dean G. Jensen; John M. Bierschwale; Robert P. Wilmington; Susan C. Adam; Manuel F. Diaz
Flight Telerobotic Servicer: Teleoperations in Microgravity BIB 126
  Spencer C. Thomason; John P. Yorchak
Fitts' Task by Teleoperator: Movement Time, Velocity, and Acceleration BIB- 127-131
  John V. Draper; Stephen Handel; Christopher C. Hood

Aging: Aging and Everyday Activities

Influence of Age on the Ability to Hear Telephone Ringers of Different Spectral Content BIBA 132-136
  J. P. Berkowitz; S. P. Casali
The failure to detect a telephone ringer signal can prove frustrating or even hazardous in certain situations, especially for older individuals who rely heavily on telephone access. This study was conducted to investigate the detectability of telephone ringer signals with individuals having elevated hearing levels. Specifically, the study investigated the detectability of three acoustically different telephone ringer signals under two masking noise conditions (quiet and 65 dBA pink noise) for two subject age groups: 20-30 years of age and over 70 years of age. Common residential telephone ringers were sampled, with three acoustically different ringers selected for study. To determine hearing ability, pure tone audiograms were administered to all subjects. Subjects' threshold levels for each ringer were then determined. Significant differences were found between the two age groups, both across telephone ringers and across noise conditions. For the older group, an advantage was found for the ringer signal which contained prominent low-to-mid range frequency components. In addition, the threshold level in noise of one ringer (a high frequency "beeper" type ringer) proved to be approximately equal to the naturally occurring decibel level of that ringer. Thus, the beeper ringer in moderate level noise (65 dBA) was effectively inaudible. The results suggest that certain electronic ringers which are currently in vogue may be unsuitable for use by the elderly or by any individual with significant high-frequency hearing loss.
Small Rotary Controls: Limitations for People with Arthritis BIB- 137-140
  Stephen Metz; Brian Isle; Sandra Denno; Wang Li
Perception of Safety Hazards across the Adult Life Span BIB- 141-145
  David B. D. Smith; James R. Watzke
Computer Communication among Older Adults BIBA 146-148
  Sara J. Czaja; M. Cherie Clark; Ruth A. Weber; Daniel Nachbar
Currently an estimated 2.8 million people aged 65 years or older need some type of assistant in carrying out everyday activities. Therefore, there exists a need to identify strategies which enhance the functional independence of older adults. There are a number of computer and communication technologies which can be used to provide support. For the potential of these technologies to be realized, they must be easy to use, easily available and accepted by older adults. The goal of this research project was to evaluate the feasibility of having older people use computers to perform tasks in their own home environment and to identify design parameters which facilitate their interaction with these systems. The study involved installing a customized e-mail system in the homes of 38 elderly women. Additional features were added over the course of the project. Data collected included: frequency of use, number and type of messages sent, communications patterns, time distribution of messages and frequency of features used. Overall the results of the study indicate that older adults are willing and able to use computers in their own homes if the system is simple, features are added in an incremental fashion and they are provided with a supportive environment.

Aging: Age-Related Slowing of Performance

Causes and Correlates of Age-Related Cognitive Slowing: Effects of Task Loading and CNS Arousal BIB- 149-153
  Michael T. Cann
Age-Related Slowing, S-R Compatibility, and Stages of Information Processing BIB- 154-157
  Virginia Diggles-Buckles; Max Vercruyssen
Age and the Elderly Internal Clock: Further Evidence for a Fundamentally Slowed CNS BIB- 158-162
  Michael T. Cann; Max Vercruyssen; P. A. Hancock
Longitudinal Analysis of Age-Related Slowing: BLSA Reaction Time Data BIB- 163-167
  James L. Fozard; Max Vercruyssen; Sara L. Reynolds; P. A. Hancock

Aging: Aging Potpourri

Older Adults Sometimes Benefit from Environmental Support: Evidence from Reading Distorted Text BIB- 168-172
  Raymond J. Shaw
Identifying the Learning Capabilities of Older Adults: Associative and Priority Learning BIB- 173-177
  Wendy A. Rogers; Arthur D. Fisk; Leonard M. Giambra; Edwin H. Rosenberg
Predictors of Alternative Scheduling: Age, Level, & Tenure BIB- 178-181
  Thomas M. Franz
Age Differences in the Adjustment to Shiftwork BIB- 182-185
  Christopher M. Keran; James C. Duchon

Communications: The Design of Communication Systems I: The Use of Voice

Effects of Speech Intelligibility among Bradley Fighting Vehicle Crew Members: SIMNET Performance and Subjective Workload BIBA 186-188
  Leslie A. Whitaker; Leslie Peters; Georges Garinther
Speech communication among crew members in military vehicles suffers from several sources which interfere with speech intelligibility. The effects of intelligibility were studied in the SIMNET Training facility at Ft. Benning, GA. Twelve Bradley-qualified, three-man crews were tested on a series of navigation and gunnery exercises. A repeated measures design was used to test five levels (0%, 25%, 50%, 75%, and 100%) of speech intelligibility. In each 10-minute exercise, the Commander used a map and mission statements to direct his crew on a 1.5 to 2.0 km course. Four check points had to be reached and one or three target vehicles destroyed. Subjective Workload Assessment Technique (SWAT) measurements were taken after each exercise. The level of speech intelligibility affected mission success and SWAT results. The impact of intelligibility was found even at the first drop in speech intelligibility (100% to 75%). We concluded that performance and operational success are adversely affected by poor speech communication. Remedial measures to radios, headsets, vehicular insulation, and hearing protection can improve speech intelligibility in these vehicles and, hence, improve performance.
The Effects of Familiarization on the Comprehension of Synthetic Speech in Telephone Communication BIBA 189-193
  Donna J. Lauretta; Robert D. Rodman; Jonathan F. Antin
Text-to-speech systems are currently used in a variety of telephone applications for remote access to information. While this form of synthetic speech may be cost-effective relative to digitized speech, the impoverished quality of the speech signal may adversely affect its comprehensibility in telephone applications. The primary objective of the present research was to investigate the amount of familiarization needed to achieve an asymptotic level of comprehension performance with high-quality synthetic speech presented in the telephone environment. Sixty-four male and female native English speakers listened to digitized natural and digitized synthetic sentences that contained relatively high and low-predictable components. Subjects provided truth-value judgments for which accuracy, response time and response certainty were measured. Results indicate that a high-predictable introductory message of approximately three relatively short sentences may improve comprehension performance of high-quality synthetic speech in some telephone applications.
User Acceptance and Preference for Advanced Voice Services Feature and Dialogue Styles BIBA 194-197
  Gerhard Deffner; Karl Melder
The experiment evaluates several alternatives for the design of user dialogues of a telephone system which integrates advanced features to accelerate access to telephone services and also Spoken Speed Dial, Call Answering and Call Delivery. In the experiment, subjects placed phone calls and relayed pieces of information. The dialogue they then encountered presented them with experimental variations of dialogue styles and provided an opportunity to use the Spoken Speed Dial feature. Subjects made 16 call attempts in the first phase of the experiment, and their preferences for dialogue features were recorded between trial blocks and at the end of the experiment. In a second phase, subjects were the recipients of Call Delivery of various types. The results show clear preference for verbal prompts, the usability of Spoken Speed Dial, conflicting attitudes towards the extra step of recording the recipient's name in Call Answering, and a preferred mode of Call Delivery.
Improving the Design of Telephone-Based Information Systems BIBA 198-202
  Michele M. Martin; Beverly H. Williges; Robert C. Williges
Telephone information systems using synthetic speech displays have become a common form of communication between a computer and a remote user. The purpose of this study was to examine five variables associated with the design of such telephone information systems: the rate of synthetic speech, the time allowed for user input, the structure of the menu hierarchy, the availability of a diagram of the menu structure, and the amount of augmented feedback provided as the user traversed the menus. Each subject completed 16 searches through the auditory database using the telephone keypad. After each search, the subject transcribed a message presented by synthetic speech. The search task was affected by all variables except feedback. The accuracy of transcription was affected only by the rate of the synthetic speech. Implications for the design of telephone information systems are discussed.

Communications: The Design of Communication Systems II: Keypads and Icons

Towards Usable Icon Sets: A Case Study from Telecommunications Engineering BIBA 203-207
  Aita Salasoo
Converging experimental tasks were used to address the development of usable interactive icon sets for telecommunications network applications. Naming and matching addressed the individual informativeness value of an icon, with naming reflecting natural context response biases and familiarity contributions more than matching. Naming also allowed intrusions to be identified early. Preference ratings simulated user behavior with iconic menus, and provided discriminability data that could help to select icons where naming and matching revealed only failures. Issues resolved and revealed during this work are discussed.
How Do You Enter "D'Anzi-Quist" Using a Telephone Keypad? BIBA 208-211
  Monica A. Marics
This study looked at the way users enter alphabetic information on a standard, 12 key telephone. Twenty subjects entered names on the telephone keypad using the one keystroke per letter method. Subjects were not given instructions on how to enter the characters Q, Z and other punctuation which do not appear on the keypad. Data were collected on the keys chosen for these special characters, and for keypress errors and name entry times. The results do not indicate a clearly preferred entry method for Q, Z and hyphen, however, apostrophes were likely to be skipped (not entered) by the subjects.
Alphabetic Input on a Telephone Keypad BIBA 212-216
  Mark C. Detweiler; Robert M., Jr. Schumacher; Nicholas L., Jr. Gattuso
With the growing use of the telephone as an input device, human factors designers need more human performance data on how quickly and accurately users can learn and execute alternative data-entry input strategies, as well as indications of what strategies users prefer. This study assesses five different strategies for entering alphabetic codes from a telephone keypad.
Evaluating the Icon-Based Interface for Words Strategy, An Augmentative Communication System BIBA 217-221
  Daryle Jean Gardner-Bonneau
The purpose of this paper is to present an evaluation of the icon-based interface employed in Words Strategy, an augmentative communication system used by speech impaired and nonspeaking individuals. Words Strategy is a software system implemented in the Prentke Romich Touchtalker, a special purpose computer which allows individuals to enter entire sentences with very few keystrokes, and which provides synthetic speech output of those sentences. The system has been criticized because of the long training period required for mastery, and because its use of multi-meaning icons might impose a severe memory load on the user (Light et al., 1988). The two studies presented derived a learning curve for Words Strategy and investigated the relearning of the system six months after initial training. The Touchtalker keyboard layout was also evaluated. Results indicated that the assignment of multiple meanings to an icon did not create a problem; in fact, it enhanced performance. In addition, relearning of the icon associations occurred rapidly, generally within one trial. The implications of the data for redesign of the Touchtalker keyboard are discussed.

Communications: Panel

Prototyping: Lessons Learned, The Good and The Not So Good BIB 222-223
  Joanne M. Walsh; Andrew D. Cohen; Dwight P. Miller; David R. Schwartz; James Wilson

Communications: The Design of Communication Systems III: Teaching and Training

The Selection of Alphanumeric Code Sequences BIBA 224-228
  Stanley C. Preczewski; Donald L. Fisher
Maintaining secure radio communications in the armed forces places an especially heavy cognitive load on all involved personnel. For example, in the Army each individual must memorize on a daily basis at least three new five character codes. The current Army code consists of the sequence letter-digit-letter followed by the sequence digit-digit (LDL-DD.) Research on paired associate learning suggests that recall could be improved by using either a letter only stimulus pair (LLL-LL) or a letter-digit stimulus pair (LLL-DD). An experiment was run to test this hypothesis. Recall for the experimental letter-digit code was over twice as good as recall for the current code.
User Interaction with Maintenance Information: A Performance Analysis of Hypertext versus Hard Copy Formats BIBA 229-233
  Bruce C. Nelson; Thomas J. Smith
Four different formats of an existing mining equipment repair manual were prepared for comparative human performance test: (1) original hard copy text; (2) improved hard copy text with enhanced readability and indexing features; (3) computerized (hypertext) version of original text; and (4) hypertext version of improved text with interactive help features. Students in a diesel mechanics class (n=55) then were tested for proficiency in accessing and understanding information presented in these different formats. The results indicate that: (1) although the users accessed the information less quickly using the computer compared with hard copy, they positively endorsed computerized hypertext presentation of maintenance information; and (2) enhanced text readability and indexing improve access to and understanding of maintenance information, but this improvement was not subjectively appreciated by the users relative to other manuals they had used. This text indicates that change to computerized maintenance manuals should be made cautiously, and that more research is needed to measure different hypertext design and training factors.
The Effectiveness of Traditional versus Computer-Based Training Techniques BIBA 234-238
  Pamela A. Savage; David G. Kemp; David R. Millen; Linda A. Roberts
The primary goal of this research was to examine the relative effectiveness of traditional versus computer-based training techniques. Additional goals were to assess how presentation modality and dynamic versus static presentation of material affects learning. Four training techniques were evaluated: paper instructions, computer simulations with on-screen text instructions, computer simulations with auditory instructions, and computer simulations with on-screen text and auditory instructions. Sixty subjects performed four tasks using a computer-based on-screen simulation of a display telephone. Before executing each task, subjects in each of the four treatment groups received a brief training session. Dependent measures consisted of time to complete the tasks, error rate, and subjective measures of how well the various training techniques were liked. An analysis of variance indicated that computer simulations with auditory instructions and simulations with combined modality instructions resulted in task performance times that were significantly less than those obtained following paper instructions. Tasks performed following computer-based training had a significantly lower error rate than did tasks performed without instructions. No significant differences were found among the training techniques for subjective measures of how well the training techniques were liked.
Human Factors in the Design of Emergency Communications Systems BIBA 239-243
  John R. Rice
The design of the user interface for emergency communications systems is critical in providing timely and appropriate response to emergency requests. With the creation of a plan to implement a national emergency number (9-1-1), more communities are choosing to centralize all emergency service communications with a single center called a public safety answering point (PSAP). This paper describes some of the issues faced in building a PSAP attendant workstation user interface for an Enhanced 9-1-1 emergency communications system. Designing a user interface for emergency communications requires a thorough understanding of the circumstances in which PSAP attendants operate. Researching the work environment of PSAP attendants has served to identify several human factors issues that became design goals for the user interface. Conducting iterative usability testing with PSAP attendants ensured the design of a usable system.

Computer Systems: Modeling

Effects of Mental Models of a Computer-Aided Instruction System on the Acquisition of Cognitive Skills BIBA 244-248
  Shang H. Hsu; John C. Chen
The human-computer interface of a computer-aided instruction (CAI) system can affect the learning of knowledge and skills. This study investigated the relative effectiveness of various mental models (i.e., metaphor, surrogate, and network) of a CAI system on the acquisition of intellectual skills and verbal information. Before the learning session started, subjects from each mental model group were given instructions about a representation of the system. Immediately after completion of the learning session, subjects were tested for their problem-solving performance. Time spent to solve each problem along with its accuracy was recorded.
   Results showed that there was an effect of mental models on the acquisition of intellectual skills. In terms of response speed and accuracy in problems requiring high complexity reasoning tasks, the Network model was most effective among the three. The Metaphor model, however, was best for problems requiring low complexity reasoning tasks.
   Mental models showed no effect on speed of the recall in verbal information. The metaphor model, however, was the best in term of recall accuracy. These results suggested that CAI systems would require different human-computer interfaces depending on types of content knowledge and task requirements.
Understanding Handwriting Recognition from the User's Perspective BIBA 249-253
  Catherine G. Wolf
As an input technique, handwriting recognition offers benefits in ease of use, but poses special problems for the user when a recognition error occurs. When a recognition error occurs, the user is often surprised since the misrecognized character often looks acceptable to him/her. In contrast, when a typing error occurs with a keyboard interface, the user immediately understands what has happened. The purpose of this study was: 1. to gain insight into what people think when a recognition error occurs, and 2. to discover whether a simple monochrome display of a user's handwriting prototypes would provide information which could be used to improve recognition accuracy. Such a display might serve as a point of reference for understanding and avoiding recognition errors. The results of the study suggested that a display of handwriting prototypes can be used by people to improve recognition accuracy. The study also found that in a large percentage of instances, people do not have any insight into the cause of a recognition error. Some possible causes for this predicament and some possible remedies are discussed in the paper.
A Cognitive Modeling Technique for Complex Decision Strategies BIBA 254-258
  Janine A. Purcell
Accurate models of operator decision making have been advocated by a number of researchers as a fundamental component of system design (Glenn, (1989); Norman, (1986); and Rasmussen, (1985)). Such models can be used to strengthen the design integrity of decision support systems in which tasks are allocated between human and computer. In this investigation, a cognitive modeling technique based on the GOMS model of Card, Moran, and Newell (1983) was used to analyze the composition and structure of decision-making strategies in a multidimensional diagnostic task. Two general strategies emerged along with the finding that certain strategies predominated according to visual display format. The methodology offers a promising approach to the analysis of verbal and retrospective protocol data solicited in conjunction with complex decision-making tasks.
Designing a Help System Using a GOMS Model: A Preliminary Method Execution Analysis BIBA 259-263
  Jay Elkerton; Steven J. Goldstein; Susan L. Palmiter
The GOMS model (Card, Moran, and Newell, 1983) was used to develop the content of a help system from the goals, operators, methods, and selection rules needed to perform HyperCard authoring tasks. Three groups of 12 novice HyperCard users performed 28 authoring tasks using either the GOMS help system, an original help system developed by Apple Computer, or no help at all (a control group). In the two help groups, users were provided the most complete help method and did not have to search for the help information. The results indicated that both help systems significantly decreased the time spent performing the authoring tasks when compared to the control group. Although a 23% decrease in execution time for GOMS users compared to original users was not significant, variance ratios confirmed that GOMS users, as a group, were more consistent when compared to original and control users. Also, GOMS users spent significantly less time per help display, translating the help methods into execution performance 78% more efficiently than original users. This result probably was due to the procedurally explicit and consistent help methods specified by the GOMS model.

Computer Systems: Panel

The Uses of Prototyping in User Interface Design and Evaluation BIBA 264-266
  Robert A. Virzi; Dick Penn; Thomas S. Tullis; Sharon L. Greene
This panel will explore the varied uses of prototyping in the user interface design process. We expect to show that there is no single thing called "user interface prototyping" and that the differences are, in many ways, greater than the similarities. Panelists have been chosen to represent a wide cross section of user interface design tasks. Collectively, members of the panel have experience in prototyping hardware and software, computer programs and telecommunications services, residential, business, and engineering applications, at various levels of fidelity, and in all parts of the design process. We expect to show how these factors all influence the way prototypes are used and that the designer must be careful in choosing the most appropriate prototyping methodology for his or her needs.
   Each panelist will begin by characterizing the portion of the design process that he or she will be talking about. This represents a major division in the way prototypes are used, both in the way that they are built and in the type of information sought by the designer. Prototypes used early in the design process (requirements analysis) tend to be of lower fidelity and are used to test preferences for design alternatives, while those used later in the design process (system specification) tend towards higher fidelity and are used to test usability. Each panelist will point out the strengths and weaknesses of his or her prototyping methodology.
   Each panelist will address the following points:
  • Appropriate uses of prototyping methodology (early vs. late in design
  • Characteristics of prototypes (platform, level of fidelity, etc.)
  • Information gathered from the prototypes (evaluate design preferences,
       measure performance, etc.)
  • Relative costs of the method (time to build, flexibility, etc.)
  • Computer Systems: Interface Design Issues

    A Comparison of Four Input Devices for the Macintosh Interface BIBA 267-271
      Sung H. Han; Gerard C. Jorna; Richard H. Miller; Kay C. Tan
    Numerous computer input devices have been designed and evaluated in the last decade. In most evaluations, simple pointing and tracking tasks were used that do not adequately represent today's computer tasks. The following research evaluated four input devices with respect to usability and preference issues. The UnMouse, the Turbo mouse, and the Felix mouse were compared with the Apple Macintosh Mouse on four different types of task: tracking (point-and-click), desktop manipulation (e.g., point, click, and drag), word processing, and graphics generation. Users expressed preferences for the devices in terms of lower-arm fatigue, precision of control, and comfort of movement. Results indicate that the Macintosh Mouse and the Felix device were quicker and preferred over the other devices.
    Design Issues for Graphical UNIX User Interfaces BIBA 272-276
      Stephanie M. Doane; Peter G. Polson; Walter Kintsch
    This paper discusses important usability issues that impact the future development of graphical user interfaces for UNIX. UNIX provides a user with the capability to combine basic commands using input/output redirection to create new commands to perform more complex tasks. The new graphical interfaces do not directly aid composing commands. However, it takes more than five years of experience to begin to be able to fluently compose new, complex commands. This paper describes a methodology which focuses attention on the problems that must be solved in order for these core features of UNIX to be accessible to individuals with one to five years of experience.
    How the Look Affects the Feel: Visual Design and the Creation of an Information Kiosk BIBA 277-281
      Gitta B. Salomon
    This paper describes a visually-oriented, iterative methodology for the design of human-computer interfaces. It focuses on the implementation of an interactive electronic information kiosk, the "CHI '89 InfoBooth." Throughout the system's design, the interdisciplinary project team concentrated on using visual materials to simulate the user's experience, rather than on writing text specifications.
       The paper discusses the role played by visual design in three phases of the system's development. It first describes how the use of "visual placeholders" -- sketchy drawings conveying interface ideas -- facilitated early design explorations. Next, it shows how "storytelling prototypes" were used to refine ideas before rigorous programming was undertaken. Finally, it describes how problems uncovered during informal user testing of functional prototypes were corrected by seemingly small changes to the interface's appearance. Specific visual examples are provided throughout.
    Screen Design for Boolean Operators BIBA 282-286
      Peter R. Nolan
    Three studies from a text search usability program are reported. A logging study revealed the most frequent kinds of searches carried out by users. A laboratory study compared three user interface design alternatives accommodating these searches. A column layout with the logical operators AND, OR, and NOT as column headings, and which assumed parentheses by the spatial positioning of the search term, was significantly faster than the other two designs, and was also preferred by a majority of the subjects. An interview study indicated that users need a verification step prior to search submittal, and a thesaurus linked to the search term fields. There is a discussion of the limitation of each screen design and an evaluation of the methodologies used.

    Computer Systems: Prototyping/Usability

    Evaluative Methods for Rapid Prototypes BIBA 287-290
      Richard D. Herring
    There are a variety of techniques that can evaluate rapid prototype design alternatives for human-machine interfaces. These techniques can be used singly, or in combination. Empirical techniques require that the analyst obtain data from respondents who exercise a rapid prototype. Empirical techniques include questionnaires, observation and unobtrusive methods of data collection, and retention tests. Analytic techniques do not require data collection, but require that the analyst have a formal description of the human-machine interface and use methods for evaluating these descriptions. Analytic techniques include structured walkthroughs, behavioral models of human-machine interaction, Operator Sequence Diagrams (OSD), and Link Analysis. Empirical and analytical techniques can lead to systems that are more likely to meet users' needs, especially when the analyst employs several techniques simultaneously.
    Streamlining the Design Process: Running Fewer Subjects BIBA 291-294
      Robert A. Virzi
    Recent attention has been focused on making user interface design less costly and more easily incorporated into the product development life cycle. This paper reports an experiment conducted to determine the minimum number of subjects required for a usability test. It replicates work done by Jakob Nielsen and extends it by incorporating problem importance into the curves relating the number of subjects used in an evaluation to the number of usability problems revealed. The basic findings are that (1) with between 4 and 5 subjects, 80% of the usability problems are detected and (2) that additional subjects are less and less likely to reveal new information. Moreover, the correlation between expert judgments of problem importance and likelihood of discovery is significant, suggesting that the most disruptive usability problems are found with the first few subjects. Ramifications for the practice of human factors are discussed as they relate to the type of usability test cycle the practitioner is employing, and the goals of the usability test.
    Usability Testing: Identifying Functional Requirements for Data Logging Software BIBA 295-299
      Brian H. Philips; Joseph S. Dumas
    One of the new tools in human factors today is usability testing. More and more human factors professionals are conducting these tests to get accurate feedback from typical users to improve the usability, overall quality, and sales of their products. American Institutes for Research has been doing usability testing for five years now and have discussed testing with the directors of many labs. We have a body of knowledge and experience from which other professionals can benefit. In particular, we will be discussing data logging software and the functional requirements for it. In this paper we will describe the requirements for data logging software to log data, edit the data log, back up data and analyze data.
       Due to the scarcity of commercially available data logging packages (we know of only one at the present time) we found it necessary to write our own software for use in our usability lab and we know others are doing the same. Based on our experience of writing and using this software, we will describe the important functional requirements for data logging software.
    Evolutionary Design of a Customer Activated Terminal: A Case Study BIBA 300-304
      Richard L. Henneman; Michael Inderrieden; Andy Anderson; Brett Taylor
    The process of designing a customer activated terminal (CAT) is described. A CAT is a self-service computer system that enables people to order food or merchandise, request information, complete banking transactions, etc. The specific application that this paper considers is a quick service restaurant lunch menu. Designers of CATs must assume that many users of such systems have no prior computer experience. One of the goals of this paper is to identify some specific interface design principles that seem to be appropriate for other CAT applications. A second goal is to illustrate how an iterative design process that focuses on user, task, and environmental characteristics can result in a successful product. The paper describes a four phase iterative development approach: data collection, initial design, testing and redesign, and implementation. Activities in each phase emphasize understanding user, task, and environmental characteristics. Several examples of the interface design at various stages of development are presented, and reasons for why design features were altered are discussed. The paper concludes by articulating several principles that apply to the design of CATs.

    Computer Systems: Panel

    Rapid Prototyping on Graphics Workstations: User's Perspective of Tools BIB 305-307
      Harold H. Miller-Jacobs; Lori C. Marchak; Daniel J. Kurys; Susan E. Campbell; Ronald G. Couture; Marian J. Murphy

    Computer Systems: Knowledge Acquisition/Expert Systems

    Human Factors Data: Knowledge Sources for Intelligent Design Associates BIBA 308-311
      Deborah Mitta; Newton C. Ellis; Dick B. Simmons
    A number of human factors data sources provide guidelines and recommendations for the system design process. Much of this information is available to the human factors engineer in design handbooks, textbooks, and periodicals. This paper will discuss the feasibility of incorporating human factors design data into intelligent, knowledge based systems referred to as design associates. Results of recent efforts to implement two types of design associates are also discussed.
    Case-Based Reasoning: Taming the Similarity Heuristic BIBA 312-315
      Leslie A. Whitaker; Richard H. Stottler; Andrea Henke; James A. King
    Case-Based Reasoning (CBR) is a methodology for employing imprecise data and uncertain information in the development of solutions to fuzzy real world problems. It is seen as an alternative to rule-based systems, which may fail under these conditions. Under the sponsorship of DARPA, we have developed a generic CBR shell.
       The system was evaluated in the domain of NACA airfoils. A subject matter expert was asked to select airfoils (cases) which were similar to target airfoils. He then defined attributes and weights by which he had judged this similarity. These parameters were then used by PROSPER in a retrieval of airfoils similar to the same targets. From a case base of 98 airfoils, PROSPER retrieved 9 out of 17 selected by the expert. After modifying the similarity algorithms, PROSPER retrieved 11 out of 17.
    A Human Factors Evaluation: The Explosive Ordnance Disposal/Automated Information Retrieval and Expert System (EOD/AIRES) BIBA 316-319
      Adam E. Krass; Robert F. Miller; Jock O. Grynovicki
    The Explosive Ordnance Disposal/Automated Information Retrieval & Expert System (EOD/AIRES) is a combination of state-of-the art computer hardware and software, developed by the U.S. Army Electronics Technology & Devices Laboratory (ETDL) to assist EOD teams in identifying and rendering safe unexploded ordnance. This study examines the identification time and error rate of using the EOD/AIRES versus using the current method, the TM-60 series manuals. Identification time was significantly reduced using the EOD/AIRES for less-experienced, U.S. Army EOD soldiers. Error rates decreased with the EOD/AIRES, but not by statistically significant amounts. The qualitative results clearly show a preference for the EOD/AIRES.
    Knowledge Acquisition Techniques: A Case Study in the Development of a Knowledge-Based System for Document Retrieval BIBA 320-324
      Steven J. Shute; Philip J. Smith
    A case study is presented describing and illustrating the use of a number of knowledge acquisition techniques for the development of a knowledge-based system. The system developed is a computerized intermediary to assist in searches of bibliographic databases. Particular emphasis is placed on a discussion of the use a conceptual model to guide in the design and analysis of an empirical study of the expertise used by human search intermediaries. The framework provided by this model made it possible to conduct a rigorous analysis of discourses that were recorded as human intermediaries assisted information seekers.

    Computer Systems: Quantifying Interface Design

    Interface Design Considered as Failure Analysis BIBA 325-328
      Thomas T. Hewett
    This paper explores some of the implications of comparing interface design with engineering design, arguing that such a comparison has typically been more misleading than fruitful. The problem, however, lies not in the comparison but in the fact that the model of engineering design most often used is an idealized one which is not representative of the actual history of the process of engineering design. When engineering design is viewed from a more realistic perspective it can be seen that design failures are both inevitable and instructive. Similarly, it can be seen that interface design, human factors, and psychology in general are very often informed more by analysis of failure than by success.
    Derivation and Validation of a Quantitative Method for the Analysis of Consistency for Interface Design BIBA 329-333
      Toshiaki Tanaka; Ray E. Eberts; Gavriel Salvendy
    Quantitative measures of consistency are formulated for human-computer interactive tasks. Two different kinds of consistency are considered: cognitive consistency and display layout consistency. Cognitive consistency is formulated by constructing the methods used for a task and the steps needed to perform the methods. A quantitative value for cognitive consistency is determined by analyzing the number of changes which would have to be made to change one method to another method. Display layout consistency is formulated by examining display parameters between two or more layouts. An experiment was performed to test the predictions of the quantitative analyses of consistency. Cognitive inconsistent tasks and inconsistent display layouts had a slightly detrimental effect on the speed of performance during an initial session. When the subjects had to return to the task several days after originally learning the task, performance on the cognitive inconsistent tasks was slower than on inconsistent display layout tasks. This latter result indicates that users will not necessarily have difficulty when learning inconsistent interactive methods but the problem will occur once the methods are learned and the user must switch between programs using inconsistent methods of interaction.

    Computer Systems: Analyzing, Designing, Developing, and Evaluating Adaptive Systems

    Analyzing, Designing, Developing, and Evaluating Adaptive Systems BIB 334-335
      James A. Carter
    The Dimensions and Degrees of Adaptation: A Synergistic Analysis BIBA 336-340
      James A. Carter
    System adaptation is necessary as organizations and individuals evolve. There are various ways in which systems can be made to adapt. By identifying the dimensions and degrees of adaptation and selecting those feasible to implement, it is possible to incorporate useful adaptive features in the systems of today.
    Juggling Concern for Completeness and Consistency with Concerns for Flexibility and Adaptability Using MOST BIBA 341-345
      James A. Carter
    The Multi-Oriented Structured Task analysis (MOST) methodology attempts to be most things to most of its users most of the time by balancing the needs of both system users and system designers for flexibility and adaptivity. The MOST methodology structures a task analysis and integrates it with other more formal specification methodologies including software engineering methodologies, human-computer interaction methodologies, and explicit user models. MOST stores these specifications in a knowledge base of four major interlinked foci for the information (users, tasks, data, and tools) and an optional foci (constraints) that can be linked to any of the major foci. The linkages in a MOST knowledge base facilitate the flexible structuring and restructuring of records. These linkages can model alternative designs and/or paths by which a system can adapt its interface while maintaining functional consistency. Various design heuristics (both software engineering and human factors) can be applied to an analysis recorded in a MOST knowledge base to assist in its transformation into a suitable design. The MOST methodology is designed to cooperate with and to assist the designer rather than to force the user to serve the methodology.
    Using the Context of Interactions to Adapt to Users BIBA 346-350
      Michael F. Schweighardt
    The context of human-computer interaction consists of those objects referred to by the users in the computer system and the users themselves. A contextual knowledge base (embedded within a computer system) can be used to facilitate and control the adaptation of the computer system based on information about users stored within this context. A general Context Management System design has been proposed and a prototype of this design implemented to meet the needs of the adaptation of systems to individuals and groups of users.

    Computer Systems: Interfacing with the User

    User Characteristics: Are Personality Types and Psychometric Factors Good Predictors? BIBA 351-355
      Raymond A. Carpenter; Ram R. Bishu; Michael W. Riley
    The objective of this investigation was to experimentally evaluate possible relationships among personality types, selected psychometric factors, and categories of cognitive activity, with an intent to develop user behavioral models for interface design. Twenty subjects (10 novice and 10 experienced) participated in an interactive scheduling task with two levels of task complexity. The task involved navigation through ten action alternatives, with each alternative being represented by a screen, to allocate resources. The subjects were administered with Myers-Briggs Type Indicator (MBTI) tests and a battery of psychometric tests. Cognitive time, total number of menu selections, total number of assignments, and the distribution of cognitive time into intelligence, design and choice activities were the performance measures. Variables derived from measurements of personality traits and psychometric factors were evaluated as predictive measures of performance. The personality trait for sensing/knowing was significant in predicting overall performance, as were psychometric factors for induction, integrative processing, and spatial scanning. The personality trait of extrovert/introvert was found to be significant in predicting the distribution of screen use times, as were derived factors for locus of control, memory ability, and personality. These results can form the basis for examining the usefulness of personality types and psychometric factors as variables in models of user characteristics.
    Menuing and Scrolling as Alternative Information Access Techniques BIBA 356-359
      Sarah J. Swierenga
    An experiment was conducted to evaluate menuing and scrolling as alternative information access techniques when a touch-sensitive input device was used to interact with the system. A hierarchical menu structure and three scrolling methods, line-by-line, half-screen, and full-screen, were tested. Level of goal word familiarity (familiar and unfamiliar) and window display size (12 or 24 lines displayed on the screen) were also examined. The task consisted of using a touch tablet to locate a target goal word with one of the four access methods. Members of a single set of 64 words, 32 familiar and 32 unfamiliar, served as goal words in all conditions. Performance data (total time to complete the task) were collected from 48 subjects. Access method and window size were between-subject variables. Each subject received both word familiarity levels. Results of an analysis of variance on mean total task time (MTIME) revealed a significant access method by word familiarity interaction. Separate analyses of variance were conducted on MTIME for familiar and unfamiliar goal word sets. When the goal word was familiar, menuing was fastest, followed by line-by-line, full-screen, and half-screen scrolling. For unfamiliar goal words, line-by-line scrolling was fastest, followed by full-screen, half-screen, and menuing. The effect of window size was not significant. The findings of this study suggest that the operator's familiarity with the information being searched is important when deciding upon an access method.
    Time Estimation of Computer "Wait" Message Displays BIBA 360-364
      Joachim Meyer; David Shinar; David Leiser
    The effect of different types computer "wait" message displays on the subjective estimates of the duration of intervals in which the subject had to wait for the computer response was studied. The displays were either static (a blank screen, the phrase PLEASE WAIT, or an epigram) or dynamic (a blinking PLEASE WAIT, a round clock-like display, or an emerging string of Xs along the center of the screen). Display duration varied from 3 to 16 seconds. The dynamic displays were shown at three different rates each. Results showed differences among the displays. For dynamic displays in which a development over time can be perceived (the clock and string of Xs), there was a direct relation between the rate of change and the estimate, i.e., higher rates of change led to estimates of longer durations. The results demonstrate that some of the variables, which have been found to influence time perception in basic psychological research settings, are applicable in the user-computer setting.

    Computer Systems: Input Devices

    Analysis of the Tony! Variable Geometry VDT Keyboard BIBA 365-369
      David A. Thompson; Janis Thomas; James Cone; Antonio Daponte; Robert Markison
    This study utilizes a variable geometry keyboard to analyze the optimal configuration for a split QWERTY-type keyboard. The measured criteria were muscle activity as measured by EMG and reported operator discomfort. A variable geometry keyboard, simultaneously adjustable in opening angle (yaw) and lateral angle (roll) was obtained. The upward slope (tilt) was preset at 10%. The study manipulated the keyboard geometry to assess the difference in musculoskeletal activity between using (1) a conventional, flat, linear keyboard; (2) a neutral, undeviated wrist position; and (3) two forearm positions that essentially eliminate pronation. Eight experienced subjects with no prior history of wrist injury of other pathology were tested. EMG activity of four relevant muscle groups was measured on each subject for each of the four keyboard positions. The study suggested an 18° opening angle and a 30°-60° lateral angle as optimal when compared with a flat, standard keyboard (they minimize objective EMG activity and subjective discomfort).
    Effect of Touch Screen Target Location on User Accuracy BIBA 370-374
      Michael Leahy; Deborah Hix
    Users can be frustrated by touch screen applications that inaccurately record their touches. Enlarging touch sensitive regions can improve touch accuracy, but few specific quantitative guidelines are available. This paper reports on a controlled experiment that investigated the effect of target location and horizontal viewing location on user accuracy. Measurements showed that persons tended to touch below the target, with touch distance increasing as the target location moved down the screen. In addition, they tended to touch toward the sides of the screen. Using collected data for each of nine screen sectors, graphs were prepared that show the relationship between touch target size and expected accuracy. For example, a 36 mm² target in the top left sector would be expected to accurately record 99% of its touches. The empirically-derived, quantitative guidelines will help designers create screens that decrease user errors and frustration.
    Target Size, Location, Sampling Point and Instructional Set: More Effects on Touch Panel Operation BIBA 375-379
      Dennis B. Beringer
    Accuracy of input using touch panel devices is affected by a number of variables which include device type, target size, and target location. It was also hypothesized that instructional set should influence performance. A screening experiment using a central-composite design (CCD) was conducted to further examine the effects of target position and size upon accuracy of the touch input. Results suggest that error for right-handed users is least near the resting position of the hand (lower right corner of display) and that shortest response times could also be obtained there. Variations in size were more likely to affect error in the Y axis and quadratic effects were present. It was also found that although instructions requiring higher precision of input from the operator did not substantially affect bias error, they did produce a reduction in variable error. It is recommended that for applications having established key input areas, positions along the lower and right-hand borders of the control/display unit should be used to minimize activation time and error. Use of the lower border exclusively can accommodate users with either a right-hand or left-hand preference. Some comments are also provided on the limitations which bound the interpretation of results in several studies and inferences thus drawn.
    The Effects of Structural and Overlay Design Parameters of Membrane Switches on the Force Exerted by Users BIBA 380-384
      Paula M. Sind
    Two experiments were conducted to evaluate the effects on applied force of structural design parameters and of feedback conditions inherent in the aesthetic overlay of membrane switch touchpads. In the first experiment which evaluated structure, 12 males and 12 females keyed 100 4-digit sequences into a computer using 6 of a total of 12 touchpads which differed in membrane ply thickness, spacer thickness, and spacer aperture diameter. The same task was completed by nine males and nine females in the second experiment, which evaluated feedback conditions inherent in flat, embossed, domed, embossed with dome, flat with escutcheon, and domed keycap aesthetic overlays. The results have important implications for the methods used for life-testing membrane switch touchpad devices and for the design of touchpads for minimizing user fatigue in extended-use keying applications.

    Computer Systems: Panel

    Real-Time GOMS: Comparative Modeling of a User-Nintendo Interaction BIB 385-386
      Wayne D. Gray; Michael E. Atwood; Judith S. Olson; Bonnie E. John; Jay Elkerton

    Computer Systems: Human-Computer Interaction

    Human-Computer Interface Quality: Part 1 -- Process or Product? BIBA 387-391
      Robert C. Schwalm
    This paper describes an on-going project to study and improve human-computer interface quality. The purpose of the project is to identify and acquire the tools and job aids needed to support high-quality human-computer interface (HCI) design. The objective is to integrate these tools in a cohesive, formal design process. The design process, supported by a suite of integrated tools, will create a design environment that promotes designer effectiveness and productivity and ensures the design of high-quality user interfaces. Formalizing the HCI design process and integrating the support tools are necessary tasks because user interface quality is not yet directly quantifiable. Quality of process is the best predictor of quality of product.
       This paper specifically describes efforts to define and measure human-computer interface quality. This paper also presents the results of a survey of human factors specialists to identify and prioritize the tools and job aids needed to be more effective and more productive in the design of high-quality user interfaces. Finally, the paper briefly addresses the need for a formalized HCI design process and integration of supporting tools and job aids.
    The Role of Human Factors Guidelines in Designing Usable Systems: A Case Study of Operating Room Equipment BIBA 392-395
      Scott S. Potter; Richard I. Cook; David D. Woods; John S. McDonald
    Recently, the Association for the Advancement of Medical Instrumentation (AAMI) adopted human engineering guidelines which represent the first formal compilation of general human factors materials for use by medical equipment designers. The applicability of these guidelines was addressed by evaluating a new microprocessor based device based on the AAMI guidelines and again using broader principles and techniques from human-computer interaction (HCI). While the device met the majority of applicable guideline recommendations, the second review identified more substantive human engineering deficiencies not addressed by the AAMI recommendations. Examples included hidden modes of operation, inconsistent signal-action mapping, complex resetting sequences, and violations of expectations. Application of these HCI issues predict confusion in using the device and limitations in diagnosing and correcting problems. Interviews with users of the device confirmed these predictions by finding that participants had major gaps, inconsistencies, and misconceptions in their mental models of the device. This investigation suggests that, in an era of microprocessor based devices, traditional human factors guidelines are only a starting point for a comprehensive approach to equipment design. To be effective as design aids (especially for designers not trained in human factors), human factors guidelines must address and incorporate HCI issues. Additionally, emphasis needs to be on methodologically oriented principles (Gould, 1988; Woods and Eastman, 1989) to aid designers in the process of design.
    Navigating Through Large Display Networks in Dynamic Control Applications BIBA 396-399
      David D. Woods; Emilie M. Roth; William F. Stubler; Randall J. Mumaw
    There is an increasing trend to use computer display systems as the primary "window" by which users see and interact with complex dynamic processes (e.g., air traffic control; computerized control rooms for process control). These kinds of applications offer special challenges to the design of computer based display systems. In particular, the large scope of these applications necessitates large display structures involving thousands of displays. Further, the dynamic nature of the tasks mean that users need to be able to move rapidly through the display structure to keep pace with temporally evolving situations and to be able to respond to new events as they occur. As a result, special display navigation challenges arise in computer based display systems for monitoring and controlling dynamic processes.
    The Video Analysis Method: An Integrated Approach to Usability Assessment BIBA 400-404
      Michael J. Prasse
    The videotape record of a user-system interaction can be very valuable in locating usability problems. However, the analysis of the videotape record is often unstructured, non-quantitative, and time consuming. The Video Analysis Method (VAM) provides a method to structure this data and derive measures of usability. A grammar integrates the videotape data with transaction log information and segments of the program code into a single representation of the interaction. Various usability metrics can then be derived from this representation. In addition, the use of the transaction log to edit usability problems from the videotape before the application of the grammar reduces the total analysis time.

    Computer Systems: Head Movement, Gestures, and Speech Input

    Target Acquisition Performance Using a Head Mounted Cursor Control Device and a Stylus with Digitizing Tablet BIBA 405-409
      Gabriel Spitz
    The ability of users to control cursor movement by tilting and nodding their head from side to side and front to back was examined in the present study. Ten non-handicapped subjects performed a target acquisition task with a head-based cursor control device and a stylus with a digitizing tablet. A similar pattern of acquisition times was found for both devices, with the stylus based performance being 2.5 times faster than head based performance. Acquisition time with both devices was significantly affected by target size and movement amplitude and could be well described by Fitts law. Acquisition times were also affected by target location. For the head-based control device it took subjects significantly longer to position the cursor in the horizontal axis than in the vertical axis, while for the stylus forward movement of the hand (up on the display) took longer. Several interpretations for these results as well as some practical implications are provided.
    Gesture Set Economics for Text and Spreadsheet Editors BIBA 410-414
      Louis A. Blatt; Alan Schell
    Since the widespread acceptance of alternative input devices and the development of technology for character recognition, gestures have begun to be investigated as a potential dialog type in software applications. Inter and intra-subject consistency has been reported; however, no one has reported inter-application consistency. This paper begins to take a systematic approach to identifying a minimal set of gestures that would be necessary to operate across a series of applications. Two tasks with 15 subjects in each were conducted on the use of gestures to edit text and spreadsheets using a pencil and paper. By examining people's editing marks in these two situations, this study begins to identify the level to which gestures remain consistent across applications. The results are discussed in relationship to the implementation of an economical gestural interface for an application suite.
    Performing Speech Recognition Research with HyperCard BIBA 415-418
      Chip Shepherd
    In the Macintosh world of computing, HyperCard, an information management software package, has become a popular tool for developing rapid-prototypes of user interfaces. The development of the first Macintosh-based speech recognizer (by Articulate Systems, Inc.) has enabled engineers at the NASA Johnson Space Center (NASA-JSC) to use HyperCard to develop prototype speech recognition interfaces for space applications. Using specifications from NASA-JSC contractor engineers, special HyperCard XCMD's were developed by Articulate Systems to assist in NASA-JSC's research applications. By working with these programs, project engineers have learned how to use them to unobtrusively collect and record quantitative speech recognition data. The objective of this report is to describe the features of the system and to instruct HF professionals how to perform speech recognition research with HyperCard.
    Comparing Touchscreen to Speech Input in the Control of a Simple Batch Process BIBA 419-423
      Mary Ann Valk
    Thirty subjects used a process control simulation to make six batches of ice cream each, using touchscreen input three times and speech input three times. Touchscreen and speech inputs were statistically compared for time to task completion, process control related errors, wrong input mode errors, input-device-related errors, total errors, and opinions about preferences and feelings of control.
       A touchscreen is the recommended operator input device for control of simple batch processes, based on the results of this experiment.

    Computer Systems: Information Presentation

    The Impact of Icons & Visual Effects on Learning Computer Databases BIBA 424-428
      David H. Merwin; Brian P. Dyre; Darryl G. Humphrey; John Grimes; John F. Larish
    Improvements in computer graphics systems have made icons and visual effects available for use in designing database interfaces. However, little research has been reported about the impact of icons and visual effects on performance measures such as item selection time and recall of the databases. The present study examined the effect of icons and visual effects on item selection time and recall of a hierarchical database structure. Information in the database was represented by either a text label or a combined icon-text label. In addition, three types of visual effects during transition between menu screens were examined: instantaneous change, zoom open from the previous screen, and dissolve into the next screen. Both the item representation and screen transition manipulations were examined between subjects. Subjects were required to reach goals by selecting items from the various menus in the database. Processing time per menu screen and recall of the database were measured for each subject. Both the type of representation (icon-text vs. text alone) and the type of transition between menus (zoom, instantaneous change or dissolve) were found to affect subjects' ability to recall the structure of the database. Furthermore, no similar effects on item selection time were found for either manipulation. These results suggest that icons and visual effects can facilitate recall of hierarchical databases without increasing traversal time. In addition, the results suggest that indiscriminate use of some visual effects (dissolve) can impair learning of computer databases.
    The Natural History of Introducing New Information Technology into a High-Risk Environment BIBA 429-433
      Richard I. Cook; David D. Woods; Michael B. Howie
    In order to study the impact of automation on complex, high consequence domains, we observed the introduction of a new computer based surgical operating room information system and its effect on cardiac anesthesiologists and their tasks. Recently developed operating room monitoring systems show considerable integration of function compared to older, discrete monitoring ensembles. The new systems differ from their predecessors in the method of display, human interface, and automation of functions previously divided between discrete monitoring elements. The results demonstrate how automation, especially clumsy automation, affects practitioner work patterns and suggests that clumsy automation constrains users in specific and significant ways.
    When It Doesn't Add Up: The Effect of Combining Command-Name Guidelines BIBA 434-438
      Kathryn F. Steinbach; Elizabeth Zoltan-Ford
    The purpose of the present study was to examine the effect of combining several command-name guidelines in the human factors literature. The particular guidelines examined included the naturalness, specificity, frequency of use, and form (words or symbols) of the command names; and the relationship among the commands within a set (i.e., congruency). Four command sets were studied: a noncompliant set that violated all five guidelines; a mixed that adhered to all five guidelines; and a symbolic and a verbal set that both violated the form guideline. Three categories of dependent variables were examined: performance (time, errors, and the use of help and cancel functions); recall; and preference measures. The results of the study indicate that the extent to which guidelines can be combined differ depending on the type of dependent variable examined. Further, the results do not support the conclusion that the more guidelines followed, the better the users's performance. The conclusions discussed include how to interpret guidelines based on past research, suggestions for combining existing guidelines, and implications for future research.
    Transfer Across Computer Command Menus BIBA 439-443
      John B. Smelcer; Neff Walker
    Two experiments are reported which examine the effects of menu organization and command naming on performance across computer command menus. Results indicate that different menu organizations are best for different selection tasks when switching between applications. Surprisingly, different sources for command names have no effect on selection times.
       When users know the exact names of the commands that they are searching for, an alphabetic organization produces faster search times in early trials. However, when users know only the definitions of the commands that they are searching for, a conceptual organization leads to faster search times in early trials. Knowledge of this conceptual organization transfers to a new application and speeds selection time in the second application. Also, similar names for identical commands transfers to the second application and improves performance there. However, keeping identical commands in the same position across applications has no effect on performance.

    Consumer Products: Design Methods and Guidelines

    Integrating Human Factors/Ergonomics in Facilitating the Design/Analysis of Consumer Products: A Computerized Knowledge-Base System BIBA 444-447
      Eileen Diaz; Shihab Asfour; Tarek Khalil; Elsayed Abdel-Moty
    An on-line, interactive and user-friendly computerized knowledge-base system is presented in this paper. It makes Human Factors information available to designers of consumer products. The Ergonomics Design Analysis Database (EDAD) requires the use of personal computer technology without extensive computer knowledge on the part of the user. The database is structured so that several screen menus provide various options for the user. The information, guidelines and dimensions are available for New Designs as well as Pre-Existing Designs.
    Designing Consumer Product Displays for the Disabled BIBA 448-451
      John T. Ward
    In this portion of an on-going effort to develop human factors guidelines for designing consumer products for the disabled a series of interviews and surveys concerning information displays was conducted in the homes of noninstitutionalized disabled people. The study covered a variety of disabilities, and where possible, individuals with several different levels of a given disability were included.
       A detailed set of recommendations of specific displays for use on products to be used by disabled people proved impractical because interfaces which were found desirable by one disabled person are often a bad choice for another. It was found that good human factors design is especially appreciated by the disabled who, in general, are very smart customers.
       The most significant display usability problem for the sensory disabled subject is the mix of displays often found on top-of-the-line products. There is a 'space-age/jet cockpit' look which seems to be popular in display design; it is not popular with the disabled. The current fad toward displaying information on a wide variety of alternating channels is likely to cause a display to be rejected by a disabled customer. In its original military/cockpit use this design approach serves the purpose of preventing the overload of any one human input channel. On household, or public access, interfaces where the intensity of information display is relatively low the use of alternating display channels often insures that a user not able to sense one of the output technologies is unable to use the device.
    Impact of Age-Related Play and Injury Patterns on Human Factors Criteria for Playground Equipment Safety BIB- 452-456
      Donna Ratte; Melanie Morrison; Neil Lerner; Marie Bellegarde

    Consumer Products: Basic Design: Controls and Displays

    Strength of Component Principles Determining Direction-of-Turn Stereotypes for Horizontally Moving Displays BIB- 457-461
      Errol R. Hoffmann
    Strength of Component Principles for Direction-of-Turn Stereotypes of Three-Dimensional Display/Control Arrangements BIB- 462-466
      Errol R. Hoffmann
    Knurls on Push and Turn Lids BIB- 467-469
      Laura Cranmer; Stephan Konz

    Consumer Products: Human Factors in Consumer Products

    Design Evaluations of Radial Arm Saws BIB- 470-472
      Kamran Abedini
    PRISMA: An Integrated Slide Management and Projection System: HF and ID Collaboration in Design BIB- 473-476
      Leon D. Segal; Jonathan Bar-Or
    A Comparative Evaluation of the Electronic Keyboard Synthesizer User Interface BIBA 477-481
      John W. Ruffner; Gary W. Coker
    A great deal of progress has been made in recent years in understanding the variables that affect the human-system interface. User interface principles have been developed and applied to the design of many military and industrial products. However, these principles are often not applied systematically to the design of the user interface of consumer products. The electronic keyboard synthesizer represents a type of consumer product in which the accurate and timely exchange of information between the system and the user during real-time system operation is essential for optimizing overall system performance. There are many similarities between the mental and physical demands of operating electronic keyboard synthesizers and operating other consumer products, such as personal computers. In many ways, synthesizers have evolved into single purpose computers. Accordingly, an understanding of the factors that affect keyboard synthesizer user interfaces can make a contribution to the understanding of consumer product interface design. This paper provides a brief, nontechnical overview of the evolutionary development of the keyboard synthesizer, discusses three technological developments that have had a major impact on the evolution of the synthesizer user interface, illustrates representative synthesizer user interface designs, and presents a comparative evaluation of the designs with respect to their adherence to user interface principles.
    Controlling and Monitoring Induced Unconsciousness: Ergonomics and Design in Anesthesia BIB- 482-485
      Sydney Hudspith

    Consumer Products: Panel

    Consumer Products and Cumulative Trauma Disorders BIBA 486-488
      Alan S. Frank; Colin Drury; Vern Putz Anderson; David J. Cochran; Stephan Konz; Stover H. Snook
    This panel focuses on the relationship between consumer products and CTD. Between the ages of 18 and 64, more people are disabled from musculoskeletal problems than any other category of disorder. Many of these disabilities are Cumulative Trauma Disorders (CTD). They result from frequent, extreme joint movements and forces.
       CTD's develop with the use of many different products. Computer terminals are often associated with Carpal Tunnel Syndrome (CTS), one type of CTD. However common household products have also been associated with CTD's. Knives, commonly found in kitchens, are also used in the meat packing industry. When used in an industrial setting, such knives are associated with CTD's. Scissors are used in the garment industry. Under conditions of high frequency use, they are associated with CTD's. Many power tools, used by both professionals and amateurs, are inappropriately used for high frequency tasks. Finally, recreational products have long been associated with injuries such as Tennis Elbow and Golfer's Elbow. The panel will discuss attributes of such products that create the potential for a CTD type injury. In addition, the panel will discuss how recreational and work activities interact to aggravate CTD's.
       The discussion will include the costs, in terms of medical expenses and lost productivity, and the prevention. Special attention will be paid to the design of products and work places to reduce the incidence and severity of such disorders.

    Consumer Products: Symbols

    Development of Camera Symbols for Consumers BIBA 489-493
      Brian Crist; David N. Aurelio
    The objective of this work was to develop a prioritized and tested set of symbols for consumer cameras and to recommend for use to the American National Standards Institute. The work was carried out in two phases, message identification and symbol construction. In the first phase, potential needs for 81 symbols for use on current and anticipated future cameras were identified. The verbal content of the symbol messages was organized into functional groups arranged around roots. Those were prioritized according to frequency of need and importance of knowing, resulting in 15 symbols to construct.
       In the symbol construction phase, concepts for pictorial representations were obtained from a previous study, from modifying existing symbols and by brainstorming. A goal was to produce at least two symbol candidates per each message for testing. Test subjects' critiques of camera symbols in a previous study were applied to the content and design.
    Consumer Evaluation of Camera Symbols BIBA 494-498
      David N. Aurelio; Brian Crist
    The goals of this research were to investigate how well 20 camera symbols communicated their intended meanings, and to determine the common characteristics of well-understood symbols which could be incorporated into other symbols. Overall, one can conclude that the best symbols did indeed have similar characteristics. These characteristics were grouped into seven fundamental factors which should be considered when designing symbols.
    Display Characteristics and Errors at a Complex Data Entry Task BIBA 499-502
      Timothy E. Kuntz; William P. Amoroso; C. Michael Lewis
    Some of the most expensive data points ever collected, outside of satellite transmissions and particle accelerators, have come from clinical trials. In large clinical studies it is common to have complex treatment protocols, large samples, and multiple distributed data collection centers. For data to be useful the study's administrators must ensure that criteria, treatments, measurements, and reporting procedures remain uniform across a large number of geographically distributed data collection sites each with its own unique administrative structure and allocation of responsibilities for the data collection task.
       PoP is a software system developed over the past seven years at the Epidemiology Data Center (EDC) in the Graduate School of Public Health at the University of Pittsburgh. PoP was designed to assist in the collection of data and to provide quality assurance for clinical trial data. Data is entered locally into microcomputers running PoP at each of the participating sites. Data entry screens are closely matched to the paper forms on which the data is collected in order to facilitate entry and reduce errors. To further reduce transcription errors, PoP requires an independent second "verification" entry of each item of the form before it can pass on to a sequence of logical checking procedures. After data has passed all local verifications it is electronically transferred to a computer at the EDC.

    Consumer Products: Warnings!

    Judgments of Hazard, Risk, and Danger: Do They Differ? BIBA 503-507
      Stephen L. Young; John W. Brelsford; Michael S. Wogalter
    There were three purposes of the present research. The first was to test whether some of the discrepancies found in the hazard and risk perception literature were due to differences between the connotations of the terms hazard and risk. The second purpose was to examine the relationship between willingness to read warnings and generalized cautious intent, as well as other relevant variables suggested by past literature. The third purpose was to examine the relation between objective measures of injury (e.g., frequencies of hospital emergency room admissions) and people's subjective perceptions. The results showed that the expressions of hazardous, risky, dangerous and hazardous-to-use connote the some meaning to lay participants. Strong intercorrelations were found between overall unsafeness (a composite of the four hazard-risk expressions), injury severity, cautious intent, and willingness to read warnings. While injury likelihood played a small part in the prediction of willingness to read warnings, the results indicated that overall unsafeness (and severity of injury) play the foremost role in people's judgments of whether to read warnings and to act cautiously. No relationship was observed between objective measures of injury frequency and people's subjective perceptions of injury likelihood which is taken as a further indication that people do not readily use injury likelihood in their judgments of product safety.
       The implications are two-fold. First, the results suggest that lay persons do not interpret the term risk in the same way as do experts. These results suggest that other terminology and language may be needed to express probability to lay persons. Second, the results suggest that designers of warnings and educational materials should focus their attention to ways that appropriately communication how badly a person can get hurt, rather than (or to a lesser extent) the likelihood of getting hurt.
    The Effect of Hazard and System Information on Estimated Risk BIBA 508-512
      Jana L. Moore
    Warning labels are used, in part, to increase risk estimates associated with hazardous equipment and products. Past research has demonstrated exposure to warning labels is related to risk estimates; however, it is not known whether warning labels cause an increase in risk estimates, as is generally assumed, or whether individuals who appreciate the danger of a situation are more likely to notice, read, and comply with warning labels. The purpose of this research was to determine the impact of two types of information on estimated risk: hazard and basic system (nonhazard) information. Research participants (77 males and 89 females) were divided into one of four information groups: 1) hazard, 2) system, 3) control, and 4) both hazard and system. As expected, hazard information, presented in a warning label, increased risk estimates. Contrary to hypothesis, system information alone did not appear to increase risk estimates. Finally, risk estimates were highest for participants who received both hazard and system information.
    Effects of Warning Explicitness on Consumer Product Purchase Intentions BIBA 513-517
      Kent P. Vaubel
    Two studies examined the relationship between the explicitness of hazard consequences described by a warning label and purchase intentions. Subjects indicated buying preferences for consumer products displaying explicit and nonexplicit warning labels. A total of 6 common consumer products was used in Experiment 1. Subjects were shown a questionnaire containing information about products varying in price, quality and warning label explicitness. Sixty-six subjects rated 2 products and ranked 2 products based on which they would be most likely to purchase. Results of the rating and ranking tasks suggest that products containing nonexplicit warnings were significantly more likely to be purchased. In Experiment 2, both explicit and nonexplicit warning labels were simultaneously presented for each of nine products and subjects rated with which warning they would prefer to buy the product. Results of Experiment 2 indicate one product was rated significantly more likely to be purchased with an explicit warning label; whereas, two products were rated more likely to be bought with nonexplicit warnings. There were no significant differences for the remaining six products. Overall, nonexplicit warnings were preferred to explicit warnings. However, this trend was reversed for one product, and for many products the detail with which a warning describes potential consequences had little effect on anticipated purchase decisions.

    Educators' Professional: Panel

    Student Participation in HFS: Benefits to Students, Benefits to the Society BIB 518-519
      Elizabeth H. Nutter; Sharolyn Converse; Rodger Koppa; R. Craig Montero; Mark S. Sanders; Paula M. Sind
    Critical Issues and Developments in Graduate Training and Continuing Education in Human Factors BIBA 520-521
      Randall M. Chambers; Hal W. Hendrick; Jefferson M. Koonce; John A. Modrick; Aaron W. Schopper; John W. Senders
    Considering the variety and sources of graduate training and continuing educational programs which lead to the science and professional practice of human factors, this panel identifies and discusses important issues and developments in the training and education of human factors specialists. Then it recommends appropriate and professional solutions and approaches to these issues from the perspectives of universities and other institutions which are engaged in human factors training and education, research and application, and the professional practice and utilization of human factors. In the training and education of human factors specialists, there are important professional and scientific issues which may be examined as the human factors discipline progresses toward accreditation and certification, and new developments and accelerated growth continue to increase professional competence and social responsibility.

    Educators' Professional: Methods and Evaluation of Human Factors Instruction

    Human Factors and Engineering Design High School Summer Workshop BIBA 522-524
      Rick Gill; Thomas Dingus
    Enrollment trends and demographics predict that the US will experience a shortfall of over 500,000 engineers within the next twenty years. The engineering community, industry and academia alike, must work together to develop programs that will motivate young men and women to pursue technical careers. The purpose of this paper is to review an annual two week high school summer workshop developed by the University of Idaho College of Engineering. Each summer selected high school students live on campus for two weeks and attend specially developed engineering classes on topics such as Engineering Mechanics, Computer Aided Design, and Human Factors and Engineering Design. Working in teams of 3 to 4, the students utilize these newly developed skills in order to solve a challenging real-world human factors engineering design problem. Student fees for the 1990 workshop were $350 which included room and board as well as university registration for two semester credit hours. Industrial and private donations helped to defray the instructional cost and to offer significant scholarship support. Student response to the workshop has been overwhelmingly positive. Suggestions for developing similar programs at other Universities are offered.
    Teaching Human Factors Design Skills: Science or Engineering Doesn't Do the Trick BIBA 525-528
      Thomas A. Dingus
    The objective of this paper is to describe a laboratory approach to teaching human factors design skills to Master's level students. A description of this approach, utilizing both engineering and scientific approaches to determine optimum design solutions is discussed. In addition, this teaching methodology is contrasted with the more common "either or" approaches found in human factors programs contained within engineering or psychology departments. The paper will also describe the training of human factors design as a skill in the form of a "hands-on" laboratory setting as opposed to a "how-to" lecture setting.
       Papers such as this provide an opportunity for educators to exchange ideas and approaches to human factors education. This is particularly important for a field as diverse as human factors, where several differing viewpoints exist.
    How Much Time Do Educators Actually Spend Teaching? (The Measurement of Faculty Productivity) BIBA 529-533
      Caroline M. Serger; Andris Freivalds
    The measurement of white collar productivity is a difficult task. This paper demonstrates one approach in defining the workload for university faculty. Even though they are educators, only 27% of their time is spent teaching or advising students (1.4%). Most is spent for research (45.4%) or service work (26.2%). Unfortunately, the usefulness of the workload model is reduced because of poor estimates of time by the faculty and the high variability found between faculty member workload estimates.
    A New Program for the Remote Training of Human Factors Professionals BIBA 534-536
      Thomas A. Dingus; Sallie E. Gordon; Richard T. Gill
    The objective of this paper is to describe a new Human Factors Master's degree program available remotely through the University of Idaho's Video Outreach program. For coursework within the program, normal classroom lectures are videotaped in a dedicated facility and produced by a video production engineer. Students can then view the lectures in one of several video formats (including VHS) in any location asynchronously as their schedules allow. This approach makes it possible for students to receive the same information as on-campus students while maintaining full time employment and/or a remote residence. As of this writing, five courses have been videotaped and a sixth is in progress. Over 60 students have taken video courses to date. Methodologies for providing high-quality video information, the need of such a program in the human factors community, data on student performance within the courses, and students reactions and evaluations are discussed.

    Environmental Design: Environmental Design Interventions

    Improving Thermal Comfort in Offices: The Impact of Underfloor Task Ventilation BIB- 537-541
      Alan Hedge; Abigail T. Michael; Sharon L. Parmelee
    An Examination of Flexible Group Work Space in the Open Office BIB- 542-546
      Linda Zimmer; Paul Cornell
    Workstation Prototypes: A Human Engineering Approach BIBA 547-551
      Thomas J. Frey; Jerry Stults
    In April 1989 a concerted effort was undertaken by the Human Factors Engineers of the IBM Federal Systems Division in Boulder, Colorado to research and design the workstation area of a mobile ground shelter. This mobile ground shelter is designed to ride and function on the trailer of a standard semi-truck. The intent was to devise a functional, human-centered design that met the specifications of tasks being performed. A series of four mockups were constructed as a way of iteratively evolving the design. This project is a good example of applied human factors principles through the evaluation of user input.
    The Application of Environmental Design Principles and Human Factors Guidelines to the Design of Training and Instructional Facilities: Room Size and Viewing Considerations BIB- 552-556
      G. F. McVey

    Environmental Design: Invited Address

    Designing Habitats to Support Long-Duration Isolation and Confinement BIB- 557-561
      Jack Stuster

    Environmental Design: Noise, Doors, Spaces, and Floors

    Effects of Fetal Exposition to Aircraft Noise on the Birthweight of Children BIB- 562-566
      A. Coblentz; A. Martel; G. Ignazi
    Use of a Visual Cue to Reduce Errors in Exiting a Crash-Bar Type Door BIB- 567-569
      Daniel F. Wallace; Deatra Huffman
    "Offensible Space" -- Law and Order Obstruction through Environmental Design BIB- 570-574
      Randall Atlas
    Floor Mats BIB- 575-579
      Malgorzata Rys; Stephan Konz

    Forensics Professional: Warnings and Automobile Safety

    Injury Severity and Likelihood in Warnings BIBA 580-583
      Michael S. Wogalter; Todd Barlow
    Two experiments examined the influence of injury likelihood and severity in warnings on product hazard perceptions (Experiment 1) and behavioral compliance (Experiment 2). In Experiment 1, participants were given a set of front panel labels for 10 household consumer products. Warnings on the labels were constructed by manipulating the likelihood (low vs. high) and severity (low vs. high) of injury. Labels lacking a warning served as controls. Participants rated the product labels under the guise of a marketing study in which most of the questions concerned product familiarity, cost, and label attractiveness. Only one question was of interest which probed the level of hazard posed by the products. The results showed that (1) the presence of a warning increased the products' judged level of hazard, (2) products with high severity warnings were viewed to be more hazardous than products with low severity warnings, and (3) likelihood of injury in the warnings had no influence on hazard perceptions.
       Experiment 2 used a chemistry laboratory demonstration task to test the effects of injury likelihood and severity in a warning on compliance behavior (i.e., wearing gloves as directed by the warning). Greater compliance was shown when warned of a more severe injury, but only when the injury was of lower likelihood.
       In general, both experiments showed that injury severity influences warning effectiveness to a greater extent than injury likelihood. The results suggest that to inform people of a hazard and to motivate them to comply with a directed behavior, product warnings should communicate the severity of consequences.
    Tire-Rim Mismatch Explosions: Human Factors Analyses of Case Studies Data BIB- 584-588
      Kenneth R. Laughery; David L. Mayer; Kent P. Vaubel
    Consumer Perception of Light Truck Safety BIB- 589-590
      Cindy LaRue; H. Harvey Cohen
    Perceptual Factors in Rear-End Crashes BIB- 591-594
      Rudolf G. Mortimer

    General Sessions: Panel

    Human Factors Engineering Standards, Guidelines, Regulations, and Practices for Medical Products and Devices BIB 595
      Christopher C. Heasly; Susan K. Meadows; Dennis I. Serig; Alan S. Berson; Gerald Chaikin
    The Human Factors of Strategic Behavior BIB 596-597
      Neville Moray; Sandra G. Hart; P. A. Hancock; Arthur F. Kramer; David L. Strayer; Christopher D. Wickens; Leon Segal; Mireille Raby; Mohamed Dessouky; Penelope M. Sanderson; Jeffrey M. James

    General Sessions: Potpourri

    Comparison of the Effects of Two Antihistamines on Cognitive Performance, Mood, and Perceived Performance BIB- 598-602
      Valerie J. Berg Rice
    The Design of a Graphics-Based Traffic Information System Based on User Requirements BIBA 603-606
      Bruce G. Gray; Woodrow Barfield; Mark Haselkorn; Jan Spyridakis; Loveday Conquest
    This paper reports the results of several studies designed to investigate commuter behavior and decision making with the goal of obtaining functional requirements for a user-based advanced driver information system (ADIS). The achieve this objective, the following tasks were performed: (1) a large sample survey was administered to 9,652 motorists commuting to a downtown location, (2) an in-depth interview was conducted focusing on the individual motorist's commute, and (3) a questionnaire was administered to investigate the relationship between various forms of graphical traffic information on commuter behavior and decision making. The information obtained from the above studies is being used to design traffic information screens that form the focal part of an ADIS.
    Coordination of Kinematic Events During Simple Arm Movements BIB- 607-610
      Jeffrey C. Woldstad

    General Sessions: Panel

    Cognitive Engineering: Directions for Future Research BIBA 611-612
      Ram R. Bishu; Raymond A. Carpenter; Donald Fisher; Sallie E. Gordon; William B. Rouse
    The need for interface systems which support human interaction with complex systems has grown in importance with the evolution of the supporting systems technology. Four levels of system performance have been identified as these systems have evolved, namely basic data processing systems (beginning in 1954, batch mode), integrated data processing systems (1960-1970 batch and interactive modes), management information systems (predominantly interactive mode), and decision support systems (1978 to present, interactive mode). To this list can now be added expert systems, and real-time advisory systems both outgrowths of technology developments in the field of artificial intelligence.

    General Sessions: Human Factors in Automotive and Transportation Applications

    Toward a Methodology for Evaluating Instrument-Panel Controls BIB- 613-617
      H. Lenora Hardee; Charles M. Johnston; James W. Kuiper; William E. Thomas
    Operability of Car Audio Controls BIB- 618-622
      Yoshimasa Osumi; Yasuhiro Inuzuka; Hideichi Ito
    In-Car Road Information: Comparisons of Auditory and Visual Presentations BIBA 623-627
      G. Labiale
    Two studies investigate the effects of presentation modalities (visual/auditory/repeated auditory) and complexity levels of different in-car road information on subjective preferences and on perceptual and cognitive performances of drivers. In real driving situations, each driver was alerted by a ringing signal prior to the presentation of a road information message or a map display associated with a road guidance message; the experimenter asked each driver over 30 s. later to recall the message or the itinerary. Results suggest that in real driving situations, short auditory road information messages or associated with map displays optimize perceptual and cognitive performances and driving safety; written messages are of greater interest if screened when the vehicle is at rest.
    Wheelchair Lifts in Public Transportations BIB- 628-631
      James W. Breaux; Jen-Gwo Chen

    General Sessions: Methods and Techniques Potpourri

    Table-Top Development, Simulation, and Evaluation Environment for Battlefield Information System Concepts BIBA 632-635
      R. Jay Ritchie; Helen Stein; Joseph N. Coco
    A software development environment for prototyping, simulating, and evaluating advanced concepts in US Army battlefield information systems was designed and implemented as a lower cost alternative to complex development and simulation facilities. The workstation-based development environment was designed to evaluate a variety of soldier-machine interface design requirements and specifications, as well as communications and database concepts for future Army vehicle and weapons systems. Using this environment, an armor maneuver control application was implemented, demonstrated, and evaluated in a networked testbed. The application demonstrated the creation and transmission of tactical graphic and text information, automatic message routing, and rapid reconfiguration of the soldier-machine interface. Use of the development environment has demonstrated that battlefield information system prototypes can be quickly and inexpensively simulated and evaluated, and can be used as an adjunct or alternative to other simulation facilities.
    The U.S. Army's New Air Defense Command and Control System: The Human Factors Design Process BIBA 636-639
      Mark W. Smith; Eric M. Grose
    TRW is currently under contract to produce the US Army's new Command, Control, and Intelligence (C²I) system for its forward areas air defense elements. The system design is characterized by automatic dissemination of tactical aircraft data as well as battlefield intelligence information. The Human Factors Engineering effort on this program has been responsible for all aspects of the design of the operator interface. The effort has focused attention on the value of interactive prototypes for the purpose of detailed design. This paper describes the Human Factors design process on this program and presents a two-phase approach to a rapid prototyping effort. Future plans to use objective data collected from prototype work in conjunction with a formal task analysis are also discussed.
    Low Cost, Real Time Simulation Based on Microcomputers BIB- 640-644
      R. Wade Allen; Jeffrey R. Hogue; Anthony C. Stein; Bimal L. Aponso; Theodore J. Rosenthal
    Adapting SMART Methodology for Use with Subjective Rating Data BIB- 645-648
      William H. Acton; John F. Courtright

    General Sessions: Panel

    Panel Discussion of "HRA -- Where Shouldst Thou Turn?": A Controversial View BIB- 649-650
      Donald L. Schurman; Barry H. Kantowitz; David D. Woods; James Reason; Thomas G. Ryan; Anthony J. Spurgin

    General Sessions: Potpourri II

    Human Factors and Human Error BIBA 651-654
      Thomas B. Malone
    One human factors method for reducing human errors involves investigation of critical incidents to understand the dynamics and etiology of human error. This paper focuses on the use of the critical incident approach to understanding human error. Specifically, the paper describes human error scenarios that occurred at Three Mile Island (TMI), Chernobyl, Bhopal, KAL-007, and the VINCENNES incident. All of the critical incidents of human error described were caused, to some extent, by human complacency with technology, by erroneous expectancies concerning what was going on in the system and in the world, and by deficiencies in the design of equipment and the training of personnel. The major lesson learned from these critical incidents is that, to avoid such disasters, complex systems must be designed in terms of the capabilities, limitations and requirements of the personnel who operate, manage, maintain or otherwise use them. Systems personnel must be considered to be an important component of the system, to be designed into the system rather than added on after system design is complete. These accidents happened because system designers failed to take into account the needs and limitations of people in the systems. Application of human factors technology in the design of complex systems will significantly reduce the potential for similar incidents occurring in the future.
    Comparing Geometric Object and Conventional Displays in Patient Monitoring BIBA 655-659
      Lee G. Deneault
    Anesthesiologists are highly trained professionals who are usually determined to maintain high standards while performing difficult tasks in life-threatening environments. Anesthesiologists must make a variety of decisions, in real-time, based on inputs from a myriad of monitoring instruments in much the some way as pilots of high performance air craft or nuclear power plant operators. Unfortunately the design of their displays is much poorer. This paper reports research aimed at extending the capabilities of the current monitoring system to integrative displays supporting the anesthesiologist's tasks of compensation and diagnosis.
    Activity and Cooperation in a Multi-Person Teleoperator Cockpit BIBA 660-663
      Christopher C. Hood; John V. Draper; Stephen Handel
    This experiment attempted to determine how members of a teleoperator crew use equipment and interact when performing remote maintenance tasks. The experiment used a modified process analysis technique to record how users performed two typical remote maintenance tasks.
       Five people participated in the experiment. They were paired into teams representing several experience levels. Participants completed the tasks while two television cameras recorded their actions on videotape. Observers later scored the videotapes using the process analysis chart. The percent of time each participant spent engaged in each activity was calculated, as was the percent of time the participants cooperated and co-acted in the cockpit. This information will be helpful in designing future teleoperator cockpits and other related control rooms.
    The Evolutionary Role of Humans in the Human-Robot System BIBA 664-668
      Thomas M. Granda; Mark Kirkpatrick; Tracye D. Julien; Larry A. Peterson
    Future human-robot systems are expected to show increasing capabilities, flexibility and levels of machine autonomy. Current systems include manufacturing robots which operate with little human intervention once they have been programmed. Teleoperators generally require continuous human control and achieve flexibility in the face of changing task requirements and environmental conditions. Human control tasks in teleoperated mobility and/or manipulator systems are often quite demanding in terms of workload and operator time. An objective of the future development of human-robot systems is incorporation of technologies such as artificial intelligence, world modeling, machine pattern recognition and automated task planning to permit increased robot autonomy and reduced human operator demands. Stages of human-robot capability were identified and criticalities of certain generic human operator functions were estimated for the capability stages. The resulting profile defines the changing role of the human operator throughout development of the capability stages. This information has implications for human factors research and development in the human-robot systems area.

    Industrial Ergonomics: Lower Back Biomechanics

    Regression Modeling of Spinal Forces During Constrained Lifting Postures BIB- 669-673
      Christopher A. Hamrick; Sean Gallagher; Arnold C. Love
    The Effects of Chair-Type and Workstation Configuration on Work Performance BIB- 674-678
      Christopher W. Rogers; Robert E. Thomas
    Comparison of Spinal Profiles While Standing, Supine, Prone, and Seated in Four Chair Types: A Pilot Study BIB- 679-683
      Wayne P. Adams; Terry L. Stentz; Brian L. Stonecipher; M. Susan Hallbeck
    Assessment of Postural Discomfort BIB- 684-687
      Rosemary Bonney; Gerald Weisman; Larry D. Haugh; Jeffrey Finkelstein

    Industrial Ergonomics: Manual Material Handling I

    Quantification of Back Motion During Manual Material Handling Tasks BIB- 688-691
      Sue Ferguson
    Evaluation of Handle Positions Using Force/Endurance Relationship of an Isometric Holding Task BIB- 692-696
      Ram R. Bishu; Ro Hae Myung; Joseph M. Deeb
    Endurance in Restricted Postures BIB- 697-701
      K. Lee; F. Aghazadeh; A. Waikar; M. Allen
    Biomechanical Modeling of Asymmetric Lifting Tasks in Constrained Lifting Postures BIB- 702-706
      Sean Gallagher; Christopher A. Hamrick; Arnold C. Love

    Industrial Ergonomics: Case Studies in Ergonomics

    Ergonomic Improvement in Games Manufacturing: A Case Study BIB- 707-709
      Robert E. Cook; Andrew J. Marcotte
    An Anthropometric Evaluation of the TH-57 Jetranger Helicopter BIB- 710-714
      Robert C. Chapleski; Edward D. Adrian
    Ergonomic Evaluation of a Cabinet Manufacturing Facility BIB- 715-719
      David E. Nestor; Thomas G. Bobick; Timothy J. Pizatella
    Human Factors Participation in the Return to Work Process BIB- 720-723
      F. Renae Bowers-Carnahan

    Industrial Ergonomics: Industrial Ergonomics Potpourri

    Static Force Exertion in Standardized, Functional and Free Postures BIB- 724-728
      Brechtje J. Daams
    Noise in Open-Plan Computer Rooms BIBA 729-733
      Anil Mital; James D. McGlothlin; Hamid F. Faard
    Noise in open-plan computer rooms and annoyance associated with it was reported to be a problem in a large service organization. An experimental investigation was undertaken to determine noise levels in this organization's computer rooms. The noise spectrum was found to be similar in all facilities investigated but substantially different from those of open-plan offices. Fifty percent of all respondents rated the noise level (on a 25-point scale) between extremely annoying and unbearable and intolerable; 10% of the respondents considered the noise very annoying; 20% of the respondents considered the noise levels moderately annoying; the remaining respondents did not seem to have a major problem. Conversational sound and computer-printer beeping sounds were reported to be most annoying by 90% of the respondents who considered the noise levels annoying.
    Performance Analysis of Acute Exposure to Hand-Arm Vibration among Underground Drillers BIB- 734-737
      Stephen D. Hudock

    Industrial Ergonomics: Workstation Design

    Effects of Keying Method, Image Preview and Work/Rest Schedule on Posture of the Remote Bar Coding Operators BIBA 738-742
      Waldemar Karwowski; Soraya Noland; Ray Eberts; Gavriel Salvendy
    The main objectives of this study were to investigate the effects of different work/rest schedules, keying methods and preview conditions on postures preferred by the remote bar coding (RBC) operators, as well as on the patterns of postural changes over time, and to relate these to the perceived postural discomfort at work. Twelve operators (nine females and three males) were hired through a local employment service. A participation requirement was a minimum typing speed of 40 correct words per minute. Three factorial (2 x 2 x 3) design with replication was used. The experiment consisted of twelve scenarios utilizing three factors, i.e. 1) keying methodology (key all or key 5 digits only), 2) image preview (none or one), and 3) work/break schedule (50 minute/10 minute, 2 hour/15 minute, or flexible schedule). The data collection for biomechanical analysis of the RBC operators was performed using the video-recording technique. Assessment of the operator's postural discomfort was performed before the work started, immediately after each work period (during the break), and immediately after the task was completed. The results of postural discomfort analysis showed the significant effects of data collection time on all reported discomfort scores. The instruction to "key all" resulted in significantly higher wrist discomfort levels than the instruction "key 5 characters only." The neck/head flexion was the lowest (mean = 30.2 degrees) for the flexible work/break schedule, and the highest (mean = 36.5 degrees) for the 50 minute work/10 minute break schedule. The preview condition resulted in smaller arm flexion (mean = 108.2 degrees) than the no preview condition (mean = 115.6 degrees). On average, the subjects used back support 34.7% of the time. When working with no image preview, the back rest was used 25% of the time. The back rest utilization increased for 50% of the time with the image preview, indicating more relaxed posture at work with the preview condition. The upper trunk angle (back inclination) assumed by the RBC operators was on average by 10 degrees greater than the angle preferred by the VDT operators.
    The Acceptability of Control Locations and Related Features in Agricultural Tractor Cabs BIB- 743-747
      Steven M. Casey; James L. Kiso
    The Development of Ergonomic Guidelines for Railroad Hand Switch Operation BIB- 748-751
      George B. Page; Paul B. McMahan; R. Todd Brown; Carter J. Kerk
    Human Factors: Added Value to Retail Customers BIB- 752-756
      Thomas J. Sluchak

    Industrial Ergonomics: Manual Material Handling II

    The Development of Preparatory Response Strategies in Anticipation of Sudden Loading of the Torso BIB- 757-761
      Steven A. Lavender
    Symmetric and Asymmetric Stoop-Lifting Strength BIB- 762-766
      Shrawan Kumar
    The Effect of Rigid Container Shape on Maximum Acceptable Weight of Lift BIB- 767-770
      Lee T. Ostrom; James L. Smith; M. M. Ayoub

    Industrial Ergonomics: Human Force Exertion

    The Role of Arm and Body Posture in Force Exertion BIB- 771-775
      Christine M. Haslegrave
    Human Force Exertion: The Influence of the Direction of the Effort BIB- 776-780
      P. Y. Hennion; A. Coblentz; R. Mollard
    Dynamic Muscle Modeling via Spectral Electromyography BIB- 781-785
      Sudhakar L. Rajulu
    A Model Describing the Time Course of Isometric Muscle Fatigue BIB- 786-790
      Joseph M. Deeb; Colin G. Drury

    Industrial Ergonomics: CTS and Hand-Wrist Biomechanics

    Carpal Tunnel Syndrome: The Design of Optimal Rate-Rest Profiles BIB- 791-794
      Donald L. Fisher; Robert O. Andres; David Airth; Steven Smith
    Isokinetic Wrist Strength of Females with Carpal Tunnel Syndrome BIB- 795-799
      Jeffrey E. Fernandez; Mary G. Klein; Valerie Learned; Robert J. Marley
    Hand-Handle Orientation and Maximum Force BIB- 800-804
      M. S. Hallbeck; D. J. Cochran; B. L. Stonecipher; M. W. Riley; R. R. Bishu
    A Dynamic Biomechanical Model of the Wrist Joint BIB- 805-809
      Richard W. Schoenmarklin; William S. Marras