hotauthor: anderson_j* : Human-Computer Interaction Bibliography Search

[1] Finding the Way to OSM Mapping Practices: Bounding Large Crisis Datasets for Qualitative Investigation Big Data and Local Society / Kogan, Marina / Anderson, Jennings / Palen, Leysia / Anderson, Kenneth M. / Soden, Robert Proceedings of the ACM CHI'16 Conference on Human Factors in Computing Systems 2016-05-07 v.1 p.2783-2795

ACM Digital Library Link

Summary: OpenStreetMap (OSM) is the most widely used volunteer geographic information system. Although it is increasingly relied upon during humanitarian response as the most up-to-date, accurate, or accessible map of affected areas, the behavior of the mappers who contribute to it is not well understood. In this paper, we explore the work practices and interactions of volunteer mappers operating in the high-tempo, high-volume context of disasters. To do this, we built upon and expanded prior network analysis techniques to select high-value portions of the vast OSM data for further qualitative analysis. We then performed detailed content analysis of the identified activity and, where possible, conducted interviews with the participants. This research allowed the identification of seven distinct mapping practices that can be classified according to dimensions of time, space, and interpersonal interaction. Our work represents a baseline for future research about how OSM crisis mapping practices have evolved over time.

[2] Are Tangibles Really Better?: Keyboard and Joystick Outperform TUIs for Remote Robotic Locomotion Control Late-Breaking Reports -- Session 1 / Nagy, Geoff M. / Young, James E. / Anderson, John E. Extended Abstracts of the 2015 ACM/IEEE International Conference on Human-Robot Interaction 2015-03-02 v.2 p.41-42

ACM Digital Library Link

Summary: Prior work has suggested that tangible user interfaces (TUIs) may be more natural and easier to learn than conventional interfaces. We present study results that suggest an opposite effect: we found user performance, satisfaction, and ease of use to be higher with more common-place input methods (keyboard and joystick) than two novel TUIs.

[3] Trust, empathy, social identity, and contribution of knowledge within patient online communities Article / Zhao, Jing / Abrahamson, Kathleen / Anderson, James G. / Ha, Sejin / Widdows, Richard Behaviour and Information Technology 2013-10-01 v.32 n.10 p.1041-1048

Link to Article at Taylor & Francis

Summary: People are increasingly utilising patient online communities (POC) to seek useful health information and empathetic support. Success of POC is reliant upon the willingness of members to contribute useful information and knowledge. Few studies have examined the influence of interpersonal bonds between members on members' contribution of information and knowledge within the context of POC. We investigated how trust, social identity, and empathy influence members' willingness to contribute knowledge to POC. Results indicated that trust and social identity within POC positively influenced the development of empathy. Empathy in turn exerted a positive influence on willingness to contribute personal knowledge and experience. Social identity also directly influenced members' willingness to contribute knowledge. The findings highlight the importance of trust, empathy, and a sense of group cohesiveness within online health settings in motivating members to contribute knowledge and support to other participants in POC.

[4] INTERNET Human-Computer Interaction Institute (HCII) / Aleven, Vincent / Anderson, John / Atkeson, Chris / Boyarski, Daniel / Cassell, Justine / Corbett, Albert / Dabbish, Laura / Date, Jenna / Dey, Anind / Evenson, Shelley / Forlizzi, Jodi / Hong, Jason / Hudson, Scott / John, Bonnie / Kam, Matthew / Kiesler, Sara / Kittur, Aniket / Klatzky, Roberta / Koedinger, Ken / Kraut, Robert / Lindqvist, Janne / Matsuda, Noboru / McLaren, Bruce M. / Morris, James / Myers, Brad / Neuwirth, Christine / Paulos, Eric / Pavlik, Philip I., Jr. / Rosé, Carolyn Penstein / Scheines, Richard / Siewiorek, Daniel P. / Stamper, John / Waibel, Alexander / Yang, Jie / Zimmerman, John 2010-08-26 2001-09-06 1998-05-22 United States, Pennsylvania, Pittsburgh Carnegie Mellon University

Keywords: education:programs | education:1st_choice | hci-sites:laboratories | labs lab laboratory

www.hcii.cmu.edu/

PhD Program

Masters Program

Undergraduate Program

[5] Privacy stories: confidence in privacy behaviors through end user programming Posters / Church, Luke / Anderson, Jonathan / Bonneau, Joesph / Stajano, Frank Proceedings of the 2009 Symposium on Usable Privacy and Security 2009-07-15 p.20

ACM Digital Library Link

[6] Privacy suites: shared privacy for social networks Posters / Bonneau, Joseph / Anderson, Jonathan / Church, Luke Proceedings of the 2009 Symposium on Usable Privacy and Security 2009-07-15 p.30

ACM Digital Library Link

[7] An evaluation of techniques for selecting moving targets Student research competition / Gunn, Tyler J. / Irani, Pourang / Anderson, John Proceedings of ACM CHI 2009 Conference on Human Factors in Computing Systems 2009-04-04 v.2 p.3329-3334

Keywords: fitts' law, moving target selection, target selection

ACM Digital Library Link

Summary: Moving targets are found in numerous applications such as computer games, air traffic control systems, and video surveillance. The selection of moving targets is considerably more difficult and error prone than traditional stationary target selection. In this paper, we introduce Comet Tails and Target Lock, two techniques that support the selection of moving targets. Our goal is to facilitate accurate and fast selection of moving targets. We compare our two techniques to unassisted selection in a controlled experiment. The results show that for moving target selection, Comet Tails and Target Lock can outperform unassisted selection, and result in fewer errors. According to post-experiment questionnaires, participants indicate a stronger preference for assisted target selection with Comet Tails and Target Lock than unassisted selection.

[8] Analysing Care Home Medication Errors: A Comparison of The London Protocol and Work Domain Analysis. COGNITIVE ENGINEERING AND DECISION MAKING: CE12 - Extensions and Applications of Cognitive Work Analysis II / Lim, Rosemary / Anderson, Janet / Buckle, Peter Proceedings of the Human Factors and Ergonomics Society 52nd Annual Meeting 2008-09-22 v.52 p.453-457

Link to HFES Digital Content

Summary: Although methods for investigating safety in complex systems have been widely applied, few studies have made explicit comparisons of two or more methods used to study one system problem. This paper presents a comparison of two methods that were used to analyse medication errors identified in UK care homes namely, The London Protocol and Work Domain Analysis (WDA). The London Protocol is based on an organisational accident causation model and WDA is the first phase of analysis in Cognitive Work Analysis (CWA) that models work domain constraints. Nine medication administration errors identified in seven care homes involving thirty-one residents were analysed. The analyses resulted in the identification of contributory factors to medication errors and changes that would improve system safety. The London Protocol was comparatively easier to use and required less time than the WDA. In The London Protocol, contributory factors were identified from a context-free list of error contributory conditions. From the identified error contributory factors, recommendations to improve system safety were made. However, it was difficult to relate these recommendations to the wider context of the system being studied. The WDA used a contextual model of the care home medication system in the form of an abstraction hierarchy (AH) to analyse errors. Factors contributing to medication errors were specific to the work domain and the resultant recommendations had broad applications, extending beyond the context of the specific errors analysed and were relevant to the whole system. The London Protocol would be a suitable analysis tool if the aim of the analysis was to generate short-term solutions in a short time and with limited financial resources. To make a long-term impact on system safety, the WDA is a useful tool. The AH can be used to analyse the current system, evaluate recommendations for system improvement, design interventions, implement strategies and used throughout the system's life cycle.

[9] Managing autonomy in robot teams: observations from four experiments Full papers / Goodrich, Michael A. / McLain, Timothy W. / Anderson, Jeffrey D. / Sun, Jisang / Crandall, Jacob W. Proceedings of the ACM/IEEE International Conference on Human-Robot Interaction 2007-03-10 p.25-32

Keywords: adjustable autonomy, dynamic autonomy, human-robot interaction, teams

ACM Digital Library Link

Summary: It is often desirable for a human to manage multiple robots. Autonomy is required to keep workload within tolerable ranges, and dynamically adapting the type of autonomy may be useful for responding to environment and workload changes. We identify two management styles for managing multiple robots and present results from four experiments that have relevance to dynamic autonomy within these two management styles. These experiments, which involved 80 subjects, suggest that individual and team autonomy benefit from attention management aids, adaptive autonomy, and proper information abstraction.

[10] Toward a real-time model-based training system / Fu, Wai-Tat / Bothell, Daniel / Douglass, Scott / Haimson, Craig / Sohn, Myeong-Ho / Anderson, John Interacting with Computers 2006 v.18 n.6 p.1215-1241

Keywords: Model-based training system; Cognitive model; Skill acquisition; Training; ACT-R; Model tracing; Augmented cognition

Link to Article at ScienceDirect

Summary: This article describes the development of a real-time model-based training system that provides adaptive '"over-the-shoulder'" (OTS) instructions to trainees as they learn to perform an Anti-Air Warfare Coordinator (AAWC) task. The long-term goal is to develop a system that will provide real-time instructional materials based on learners' actions, so that eventually the initial set of instructions on a task can be strengthened, complemented, or overridden at different stages of training. The training system is based on the ACT-R architecture, which serves as the theoretical background for the cognitive model that monitors the learning process of the trainee. An experiment was designed to study the impact of OTS instructions on learning. Results showed that while OTS instructions facilitated short-term learning, (a) they took time away from the processing of current information, (b) their effects tended to decay rapidly in initial stages of training, and (c) their effects on training diminished when the OTS instructions were proceduralized in later stages of training. A cognitive model that learned from both the upfront and OTS instructions was created and provided good fits to the learning and performance data collected from human participants. Our results suggest that to fully capture the symbiotic performance between humans and intelligent training systems, it is important to closely monitor the learning process of the trainee so that instructional interventions can be delivered effectively at different stages of training. We proposed that such a flexible system can be developed based on an adaptive cognitive model that provides real-time predictions on learning and performance.

[11] On the role of metaphor and language in design of third party payments in eBanking: Usability and quality / Weir, Catherine S. / Anderson, James N. / Jack, Mervyn A. International Journal of Human-Computer Studies 2006 v.64 n.8 p.770-784

Keywords: Usability; User-interface; Design; Internet Banking; Experiment

Link to Article at ScienceDirect

Summary: This paper describes results of a usability study of contrasting user-interface designs for Internet Banking (eBanking). Two specific interface metaphors were compared in the first experiment, linear form filling and array editing interaction modes. Terminology in the interaction dialogue was compared in the second experiment, using typical banking language and a generic, plain language interface. This research aimed to perform usability evaluation and comparison of the alternative interface designs to illuminate the development of new eBanking services. This research involved sixty-one participants (Internet users and customers of the involved Bank) exploring the designs in controlled experiments involving hands-on experience. Banks are interested in ensuring their eBanking services are highly customer-centric and that the interface matches customer expectations in order to drive customers towards this lower cost channel. The results of the first experiment (N=32, where N indicates the number of participants in the cohort) concluded that the simple form-filling metaphor, taken from the traditional paper-based procedure, was generally more usable than a Spreadsheet metaphor. In the second experiment (N=29), it was found that although banking terminology was not completely understood across the cohort, the instructional language changes did not impact significantly on usability.

[12] Crew Resource Management Training and Young Driver Safety TRAINING: Conceptual and Technological Innovations in Training / Regan, Michael / Salmon, Paul / Mitsopoulos, Eve / Anderson, Janet / Edquist, Jessica Proceedings of the Human Factors and Ergonomics Society 49th Annual Meeting 2005-09-26 v.49 p.2192-2196

Link to HFES Digital Content

Summary: Compared to other age groups, young novice drivers have a higher risk of being involved in road crashes. Recent research has indicated that, depending on certain passenger and driver characteristics, passengers can have either a positive or negative influence on driver behaviour and also that the principles of Crew Resource Management (CRM) training might be beneficial in addressing some of the problems associated with young driver behaviour when in the presence of passengers. This paper describes a program of research that was undertaken in order to investigate the potential application of CRM training principles within young driver training programs in the Australian Capital Territory (ACT), a jurisdiction located in South-East Australia. The findings indicate that the application of CRM principles within young driver training is a viable concept to pursue, and that such interventions have the potential to significantly enhance the positive, and reduce the negative effects of passengers on young driver behaviour. In conclusion to this research, a set of recommendations for the development of an ACT-based trial young driver CRM training program are proposed, and recommendations for further research regarding CRM and driver training are discussed.

[13] Designing Sonification for Effective Attentional Control in Complex Work Domains PERCEPTION AND PERFORMANCE: Auditory Displays and Sonification / Anderson, Janet / Sanderson, Penelope Proceedings of the Human Factors and Ergonomics Society 48th Annual Meeting 2004-09-20 v.48 p.1818-1822

Link to HFES Digital Content

Summary: Complex safety-critical work domains such as anesthesia require human operators to direct their attention appropriately. A sonification is a possible method for directing attention to relevant changes while still allowing monitoring under divided attention conditions. However, there is currently little information to guide the design of sonification. Two experiments investigated the effect of the number of auditory streams on ability to detect changes (Experiment 1), and the effect of the number of auditory streams under different attention conditions (Experiment 2). When monitoring with selective attention, participants noted changes more accurately with three streams than with one or two streams, but when there were also distracter changes participants noted changes more accurately in multiple streams. Overall, accuracy was lower when attention was divided than when it was selective, but accuracy was especially low in the three-stream configuration. Distracter changes increased divided attention accuracy. The results suggest that the number of streams should be minimized if operators' attention will be divided between monitoring and other tasks.

[14] The role of auditory attention and auditory perception in the design of real-time sonification of anaesthesia variables In the hospital theatre / Anderson, Janet / Sanderson, Penelope / Norris, Michael Proceedings of OZCHI'02, the CHISIG Annual Conference on Human-Computer Interaction 2002-11-25 p.11

Keywords: sonification, auditory attention, auditory perception, auditory display

www.ozchi.org/proceedings/2002/Hpapers/Paper%2076%20Janet%20Anderson.htm

www.ozchi.org/proceedings/2002/Ppapers/Paper%2076%20Janet%20Anderson.pdf

Summary: Sonification -- the representation of data relations in sound relations -- is attracting increasing attention within the human factors community as a way of providing human operators of real-time processes with continuous information about the state of a system. This is particularly needed in anesthesia, where the anesthetist must divide attention across a wide variety of tasks. Efforts to design effective sonifications of the physiological state of anesthetized patients, however, have not emerged from basic scientific studies of auditory attention. Literature reviews indicate that the kind of basic scientific research on auditory attention that would support the design of sonifications does not exist. The work described herein is the first part of a research program in which we build a foundation for our design of anesthesia sonification in a series of basic studies of auditory attention. These studies may contribute information that will support sonification design beyond the anaesthesia application.

[15] Sonification Design for Real-Time Processes: Issues and a Demonstration. PERCEPTION AND PERFORMANCE: Displays and Controls I [Lecture] / Anderson, Janet / Sanderson, Penelope Proceedings of the Human Factors and Ergonomics Society 46th Annual Meeting 2002-09-30 v.46 p.1574-1578

Link to HFES Digital Content

Summary: While interest is growing in the possible advantages of sonifiying physiological information in the operating room, principles to guide the design of sonifications have not been fully developed. An unresolved question concerns the number of auditory streams that can be monitored and the number of auditory dimensions carrying information within a stream that can be monitored. This question has implications for the effective operation of selective and divided attention. This experiment explored the perceptual limits of attending to six acoustic parameters of one sound stream. A range of discriminable differences was developed for each of six acoustic parameters. Performance on a discrimination task for all six acoustic parameters was significantly different from chance when only one acoustic parameter changed. Performance levels significantly different from chance were obtained for five of the six acoustic parameters when one other distractor parameter also changed. However, performance dropped to below chance for all parameters when five distractor parameters also changed. The results are discussed in the context of ongoing research that approaches the design problem from both a perceptual perspective and a cognitive, strategic perspective.

[16] Partitioning Visual Displays: Directing the Path of Visual Search PERCEPTION AND PERFORMANCE: Search and Attention [Lecture] / Haimson, Craig / Anderson, John R. Proceedings of the Human Factors and Ergonomics Society 46th Annual Meeting 2002-09-30 v.46 p.1604-1608

Link to HFES Digital Content

Summary: We reduced time to detect target symbols in mock radar screens by partitioning displays in accordance with task instructions. Targets appeared among distractor symbols either close to or far from the display center, and participants were instructed to find the target closest to the center. Search time increased with both number of distractors and distance of target from center, and the effect of distractors was considerably greater for far than close targets. However, when close and far regions were delineated by a centrally-presented "range ring", the distractor effect was substantially reduced, especially for far targets. We suggest that range rings focus attention on specific regions of the screen and aid in the determining of which regions have already been searched.

[17] Locus of Feedback Control in Computer-Based Tutoring: Impact on Learning Rate, Achievement and Attitudes Structuring Software and Systems for Learning / Corbett, Albert T. / Anderson, John R. Proceedings of ACM CHI 2001 Conference on Human Factors in Computing Systems 2001-03-31 p.245-252

Keywords: feedback in problem solving, instructional interface design, intelligent tutoring systems, student modeling

Broken Link to ACM Digital Library

Summary: Five public school teachers were observed during two self-study sessions where they learned to use Visual AgenTalk (VAT). The first session emphasized the basic visual programming skills, while the second introduced ways to reuse existing simulations. Two versions of the reuse tutorial were developed, one offering a concrete example world for reuse, and the second an abstract world. During their learning and reuse sessions, the teachers thought out loud as they worked, enabling a detailed analysis of their goals, reactions, problems, and successes. After each session, the teachers also completed user reaction questionnaires. Although all teachers succeeded in learning the basics of VAT, they varied considerably in their reuse of the example simulations. It appears that the simplified components of the abstract world supported reuse to a greater degree than those of the concrete example world.

[18] What can a mouse cursor tell us more?: correlation of eye/mouse movements on web browsing Short talks: of mice and measures / Chen, Mon Chu / Anderson, John R. / Sohn, Myeong Ho Proceedings of ACM CHI 2001 Conference on Human Factors in Computing Systems 2001-03-31 v.2 p.281-282

ACM Digital Library Link

Summary: In this paper, we describe a study on the relationship between gaze position and cursor position on a computer screen during web browsing. Users were asked to browse several web sites while their eye/mouse movements were recorded. The data suggest that there is a strong relationship between gaze position and cursor position. The data also show that there are regular patterns of eye/mouse movements. Based on these findings, we argue that a mouse could provide us more information than just the x, y position where a user is pointing. This implies that we can use an inexpensive and extremely popular tool as an alternative of eye-tracking systems, especially in web usability evaluation. Moreover, by understanding the intent of every mouse movement, we may be able to achieve a better interface for human computer interaction.

[19] Automated Eye-Movement Protocol Analysis / Salvucci, Dario / Anderson, John R. Human-Computer Interaction 2001 v.16 n.1 p.39-86

Summary: This article describes and evaluates a class of methods for performing automated analysis of eye-movement protocols. Although eye movements have become increasingly popular as a tool for investigating user behavior, they can be extremely difficult and tedious to analyze. In this article we propose an approach to automating eye-movement protocol analysis by means of tracing-relating observed eye movements to the sequential predictions of a process model. We present three tracing methods that provide fast and robust analysis and alleviate the equipment noise and individual variability prevalent in typical eye-movement protocols. We also describe three applications of the tracing methods that demonstrate how the methods facilitate the use of eye movements in the study of user behavior and the inference of user intentions.

[20] Eye-Movements During Unit-Task Execution in a Complex Problem-Solving Situation 2: TRAINING: Human Performance Models in Training Systems [Single-Session Symposium] / Sohn, Myeong-Ho / Douglass, Scott A. / Chen, Mon-Chu / Anderson, John R. Proceedings of the Joint IEA 14th Triennial Congress and Human Factors and Ergonomics Society 44th Annual Meeting 2000-07-30 v.44 n.2 p.378-381

Link to HFES Digital Content

Summary: We have studied the performance of subjects as they acquired skill in the Georgia Tech Aegis Simulation Program (GT-ASP) with a particular focus on their eye movements. Our task analysis showed that the GT-ASP breaks down into the selection of unit tasks and the execution of these unit tasks. We focused on the Identification unit-task. Our results showed that most of the practice benefit in Identification came from increasing efficiency during cognitive process, in which people make inferences and decisions on the basis of the currently available information. We also analyzed eye fixations when people perform this unit-task. Participants showed different fixation patterns, depending on what portion of the unit-task was being executed. Fluency in a dynamic complex problem-solving seems to be achieved by efficiency in cognitive as well as perceptual processes.

[21] Concrete Form Work, Injury and Musculoskeletal Disorders 5: MULTIPLE-SESSION SYMPOSIA: Surveillance and Monitoring [Research] / Welch, Laura S. / Hunting, Katherine L. / Anderson, Judith Proceedings of the Joint IEA 14th Triennial Congress and Human Factors and Ergonomics Society 44th Annual Meeting 2000-07-30 v.44 n.5 p.647-650

Link to HFES Digital Content

Summary: We present hospital emergency room data on 154 injuries of carpenters and laborers working for one contractor on one large project over four years. This contractor was in charge of concrete form construction, a task that entails significant ergonomic risks. The carpenters working for this contractor had a higher percentage of injuries diagnosed as strains and sprains, while the laborers had more injuries from "struck-by/struck-against" than other crafts. We will discuss possible strategies to decrease ergonomic hazards and injuries in form construction.

[22] Intelligent Gaze-Added Interfaces Eye Gaze / Salvucci, Dario D. / Anderson, John R. Proceedings of ACM CHI 2000 Conference on Human Factors in Computing Systems 2000-04-01 v.1 p.273-280

Keywords: Gaze-added interfaces, Gaze-based interfaces, Intelligent interfaces, Eye movements, User models

888 KB

Broken Link to ACM Digital Library

Summary: We discuss a novel type of interface, the intelligent gaze-added interface, and describe the design and evaluation of a sample gaze-added operating-system interface. Gaze-added interfaces, like current gaze-based systems, allow users to execute commands using their eyes. However, while most gaze-based systems replace the functionality of other inputs with that of gaze, gaze-added interfaces simply add gaze functionality that the user can employ if and when desired. Intelligent gaze-added interfaces utilize a probabilistic algorithm and user model to interpret gaze focus and alleviate typical problems with eye-tracking data. We extended a standard WIMP operating-system interface into a new interface, IGO, that incorporates intelligent gaze-added input. In a user study, we found that users quickly adapted to the new interface and utilized gaze effectively both alone and with other inputs.

[23] Minimalist User Modelling in a Complex Commercial Software System / Strachan, Linda / Anderson, John / Sneesby, Murray User Modeling and User-Adapted Interaction 2000 v.10 n.2/3 p.109-146

Keywords: pragmatic user modeling; knowledge-based systems; empirical evaluation; commercial software systems; financial planning

link.springer.com//article/10.1023/A%3A1026553509852

Summary: While user modelling has produced many research-based systems, comparatively little progress has been made in the development of user modelling components for commercial software systems. The development of minimalist user modelling components which are simplified to provide "just enough" assistance to a user through a pragmatic adaptive user interface is seen by many as an important step toward this goal. This paper describes the development, implementation, and evaluation of a minimalist user modelling component for the Tax and Investment Management Strategizer (TIMS), a complex commercial software system for financial management. This user modelling component manages several levels of adaptations designed to assist novice users in dealing with the complexity of this software package. Important issues and considerations for the development of user modelling components for commercial software systems and the evaluation of such systems in commercial settings are also discussed.

[24] Eye Tracking the Visual Search of Click-Down Menus Cognitive Models of Screen Interaction / Byrne, Michael D. / Anderson, John R. / Douglass, Scott / Matessa, Michael Proceedings of ACM CHI 99 Conference on Human Factors in Computing Systems 1999-05-15 v.1 p.402-409

Keywords: Menu selection, Eye tracking, Visual search, Cognitive models

Broken Link to ACM Digital Library

Summary: Click-down (or pull-down) menus have long been a key component of graphical user interfaces, yet we know surprisingly little about how users actually interact with such menus. Nilsen's [8] study on menu selection has led to the development of a number of models of how users perform the task [6, 21. However, the validity of these models has not been empirically assessed with respect to eye movements (though [1] presents some interesting data that bear on these models). The present study is an attempt to provide data that can help refine our understanding of how users interact with such menus.

[25] Third generation computer tutors: learn from or ignore human tutors? Panel / Corbett, Albert / Anderson, John / Graesser, Art / Koedinger, Ken / VanLehn, Kurt Proceedings of ACM CHI 99 Conference on Human Factors in Computing Systems 1999-05-15 v.2 p.85-86

ACM Digital Library Link

Summary: Current "second generation or "intelligent" computer tutors are approximately one-half as effective as human tutors. How will we develop the next generation of computer tutors that approaches human tutor effectiveness? Does success lie in understanding and emulating the performance of human tutors? If so, should we focus on natural language dialog or human tutor pedagogy? Alternatively, does computer technology afford effective instructional interventions, unavailable to human tutors? Can we modify learning activities and monitor student problem solving in ways that human tutors cannot.