Number of co-authors:25
Number of publications with 3 favourite co-authors:Wayne D. Gray:5Wei Dong:4Ruogu Kang:4
Wai-Tat Fu's 3 most productive colleagues in number of publications:Peter Pirolli:46Wayne D. Gray:45Wei Dong:9
Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away.
-- Antoine de Saint Exupéry
Read the fascinating history of Wearable Computing, told by its father, Steve Mann
Read Steve's chapter !
Our Latest Books
Kumar and Herger 2013: Gamification at Work: Designing Engaging Business Software...
by Janaki Mythily Kumar and Mario Herger
Whitworth and Ahmad 2013: The Social Design of Technical Systems: Building technologies for communities...
by Brian Whitworth and Adnan Ahmad
Soegaard and Dam 2013: The Encyclopedia of Human-Computer Interaction, 2nd Ed....
by Mads Soegaard and Rikke Friis Dam
Has also published under the name of:
Personal Homepage: cs.illinois.edu/homes/wfu/
Publications by Wai-Tat Fu (bibliography)
Dong, Wei and Fu, Wai-Tat (2012): One piece at a time: why video-based communication is better for negotiation and conflict resolution. In: Proceedings of ACM CSCW12 Conference on Computer-Supported Cooperative Work 2012. pp. 167-176.
We compared the effects of three computer mediated communication (CMC) channels (text, audio, and video) on how people performed an appointment-scheduling task. The task involved a grounding and a conflict resolution component. The results showed that video conferencing supported participant dyads in reaching a consensus that had better balanced performance between the dyads only when task difficulty was high and when there were more inherent conflicts in the task. Participants across the three CMC conditions also demonstrated different patterns of conversation dynamics during information exchange and negotiation. Mediation analysis showed that in video-based communication, strategies of exchanging less information at a time predicted higher levels of negotiation, which in turn predicted smaller performance differences in high conflict conditions. The results suggested that the design and use of communication technologies for remote conflict resolution should promote the strategy of exchanging information in small pieces, which could better support subsequent negotiation and foster a sense of fairness.
© All rights reserved Dong and Fu and/or ACM Press
Huang, Shih-Wen, Tu, Pei-Fen, Amamzadeh, Mohammad and Fu, Wai-Tat (2012): Review explorer: an innovative interface for displaying and collecting categorized review information. In: Adjunct Proceedings of the 2012 ACM Symposium on User Interface Software and Technology 2012. pp. 83-84.
Review Explorer is an interface that utilizes categorized information to help users to explore a huge amount of online reviews more easily. It allows users to sort entities (e.g. restaurants, products) based on their ratings of different aspects (e.g. food for restaurants) and highlight sentences that are related to the selected aspect. Existing interfaces that summarize the aspect information in reviews suffer from the erroneous predictions made by the systems. To solve this problem, Review Explorer performs a real-time aspect sentiment analysis when a reviewer is composing a review and provides an interface for the reviewer to easily correct the errors. This novel design motivates reviewers to provide corrected aspect sentiment labels, which enables our system to provide more accurate information than existing interfaces.
© All rights reserved Huang et al. and/or ACM Press
Kang, Ruogu, Fu, Wai-Tat and Kannampallil, Thomas George (2010): Exploiting knowledge-in-the-head and knowledge-in-the-social-web: effects of domain expertise on exploratory search in individual and social search environments. In: Proceedings of ACM CHI 2010 Conference on Human Factors in Computing Systems 2010. pp. 393-402.
Our study compared how experts and novices performed exploratory search using a traditional search engine and a social tagging system. As expected, results showed that social tagging systems could facilitate exploratory search for both experts and novices. We, however, also found that experts were better at interpreting the social tags and generating search keywords, which made them better at finding information in both interfaces. Specifically, experts found more general information than novices by better interpretation of social tags in the tagging system; and experts also found more domain-specific information by generating more of their own keywords. We found a dynamic interaction between knowledge-in-the-head and knowledge-in-the-social-web that although information seekers are more and more reliant on information from the social Web, domain expertise is still important in guiding them to find and evaluate the information. Implications on the design of social search systems that facilitate exploratory search are also discussed.
© All rights reserved Kang et al. and/or their publisher
Chin, Jessie and Fu, Wai-Tat (2010): Interactive effects of age and interface differences on search strategies and performance. In: Proceedings of ACM CHI 2010 Conference on Human Factors in Computing Systems 2010. pp. 403-412.
We present results from an experiment that studied the information search behavior of younger and older adults in a medical decision-making task. To study how different combination of tasks and interfaces influenced search strategies and decision-making outcomes, we varied information structures of two interfaces and presented different task descriptions to participants. We found that younger adults tended to use different search strategies in different combination of tasks and interfaces, and older adults tended to use the same top-down strategies across conditions. We concluded that older adults were able to perform mental transformation of medical terms more effectively than younger adults. Thus older adults did not require changing strategies to maintain the same level of performance.
© All rights reserved Chin and Fu and/or their publisher
Dong, Wei and Fu, Wai-Tat (2010): Cultural difference in image tagging. In: Proceedings of ACM CHI 2010 Conference on Human Factors in Computing Systems 2010. pp. 981-984.
Do people from different cultures tag digital images differently? The current study compared the content of tags for digital images created by two cultural groups: European Americans and Chinese. In line with previous findings on cultural differences in attentional patterns, we found similar cultural differences in the order of the image parts (e.g., foreground or background objects) that people tag. We found that for European Americans, the first tag was more likely assigned to the main objects than that by Chinese; but for Chinese, the first tag was more likely assigned to the overall description or relations between objects in the images. The findings had significant implications for designing cultural-sensitive tools to facilitate the tagging and search process of digital media, as well as for developing data-mining tools that identify user profiles based on their tagging patterns and cultural origins.
© All rights reserved Dong and Fu and/or their publisher
Fu, Wai-Tat and Kannampallil, Thomas George (2010): Cognitive models of user behavior in social information systems. In: Proceedings of ACM CHI 2010 Conference on Human Factors in Computing Systems 2010. pp. 4485-4488.
The widespread popularity and adoption of social information systems ranging from social networking systems to social book marking systems has resulted in an increased research focus on studying user interactions in such systems. Recent research literature has reported on analysis of large datasets of logs of social interactions as a way to describe the structure of these systems and to characterize individual behavior. There is significantly limited research on cognitive behavior of individual users in social information systems. Research on individual behavior can help us develop nuanced perspectives of social information use and can provide insights for developing more effective systems for users.
© All rights reserved Fu and Kannampallil and/or their publisher
Fu, Wai-Tat, Kannampallil, Thomas G. and Kang, Ruogu (2010): Facilitating exploratory search by model-based navigational cues. In: Proceedings of the 2010 International Conference on Intelligent User Interfaces 2010. pp. 199-208.
We present an extension of a computational cognitive model of social tagging and exploratory search called the semantic imitation model. The model assumes a probabilistic representation of semantics for both internal and external knowledge, and utilizes social tags as navigational cues during exploratory search. We used the model to generate a measure of information scent that controls exploratory search behavior, and simulated the effects of multiple presentations of navigational cues on both simple information retrieval and exploratory search performance based on a previous model called SNIF-ACT. We found that search performance can be significantly improved by these model-based presentations of navigational cues for both experts and novices. The result suggested that exploratory search performance depends critically on the match between internal knowledge (domain expertise) and external knowledge structures (folksonomies). Results have significant implications on how social information systems should be designed to facilitate knowledge exchange among users with different background knowledge.
© All rights reserved Fu et al. and/or their publisher
Dong, Wei and Fu, Wai-Tat (2010): Toward a cultural-sensitive image tagging interface. In: Proceedings of the 2010 International Conference on Intelligent User Interfaces 2010. pp. 313-316.
Do people from different cultures tag digital images differently? The current study examined the relationship between the position and content of tags for digital images created by participants from two cultural groups (European Americans and Chinese). In line with previous findings on cultural differences in attentional patterns, we found cultural differences in the order of the parts of images people chose to tag. European Americans tended to tag main objects first, and tag background objects and overall properties in the images later; in contrast, Chinese tended to tag the overall properties first, and tag the main and background objects later. Based on findings of the current study, we discuss implications on developing a cultural-sensitive algorithm to facilitate the tagging and search process of digital media and data-mining tools to identify user profiles based on their cultural origins.
© All rights reserved Dong and Fu and/or their publisher
Kang, Ruogu and Fu, Wai-Tat (2010): Exploratory information search by domain experts and novices. In: Proceedings of the 2010 International Conference on Intelligent User Interfaces 2010. pp. 329-332.
The arising popularity of social tagging system has the potential to transform traditional web search into a new era of social search. Based on the finding that domain expertise could influence search behavior in traditional search engines, we hypothesized and tested the idea that domain expertise would have similar influence on search behavior in a social tagging system. We conducted an experiment comparing search behavior of experts and novices when they searched using a tradition search engine and a social tagging system. Results from our experiment showed that experts relied more on their own domain knowledge to generate search queries, while novices were influenced more by social cues in the social tagging system. Experts were also found to conform to each other more than novices in their choice of bookmarks and tags. Implications on the design of future social information systems are discussed.
© All rights reserved Kang and Fu and/or their publisher
Wang, Yi, Dong, Wei and Fu, Wai-Tat (2010): To Customize or Not to Customize The Use of a Customization Tool to Augment Information Indexing in a Computer Desktop Environment. In: Proceedings of the Human Factors and Ergonomics Society 54th Annual Meeting 2010. pp. 605-609.
We studied when and how people will use a customization tool that helps users offload information indexing to the external environment to augment finding and re-finding of information in a computer desktop environment. An experiment was conducted to study how the cost and benefit of customization may influence when and how participants customize, and how the customization may help them find and re-find information. Results showed that participants were sensitive to the cost and benefit of customization. In general, participants performed more customization when the cost was low and when the benefit was high. Customization was also found to influence their information indexing strategy. Implications to design of customization tools for information indexing were discussed.
© All rights reserved Wang et al. and/or HFES
Waicekauskas, Kevin T., Kannampallil, Thomas G., Kopren, Katie, Tan, Pei-Hsiu, Fu, Wai-Tat and Morrow, Daniel G. (2010): Collaborative Tools in a Simulated Patient-Provider Medication Scheduling Task. In: Proceedings of the Human Factors and Ergonomics Society 54th Annual Meeting 2010. pp. 1936-1940.
Medication adherence is an essential activity for successful self-care, particularly for older adults who take multiple medications. Adherence depends on understanding how to take medication, which in turn depends on effective communication with providers. Unfortunately, physician and patient communication is often substandard and ineffective. Furthermore, successful adherence is often tied to supporting the patient's prospective memory by integrating medication taking with a daily routine. We have developed a paper-based tool (MedTable) for supporting provider-patient collaborative planning about taking medication, which has improved performance in a simulated medication scheduling task. The tool is used as an external workspace that reduces cognitive demands while also facilitating collaboration in a planning task. In the current study, the MedTable was redesigned and an electronic version was also developed. Both tools were compared to a less structured paper tool similar to medication reconciliation cards used in many health care settings (Medcard). 144 community dwelling older adults (aged 60 and over) participated in pairs in a simulated patient-provider medication scheduling task. Each pair solved four medication scheduling problems (2 simple and 2 complex) using one of the three tools (MedTable, e-MedTable, Medcard). Although all three tools supported highly accurate solutions, the MedTable produced significantly more accurate schedules than the Medcard (there were no tool differences in solution time). Moreover, participants rated workload associated with problem solving as lower for the two structured tools compared to the Medcard. The MedTable was also rated more usable than the non-structured aid. Finally, there was no evidence that older adults had difficulty using the computer-based tool, which suggests that a computer-based tool could be an effective intervention for improving provider-patient collaboration.
© All rights reserved Waicekauskas et al. and/or HFES
Fu, Wai-Tat, Kannampallil, Thomas, Kang, Ruogu and He, Jibo (2010): Semantic imitation in social tagging. In ACM Transactions on Computer-Human Interaction, 17 (3) p. 12.
We present a semantic imitation model of social tagging and exploratory search based on theories of cognitive science. The model assumes that social tags evoke a spontaneous tag-based topic inference process that primes the semantic interpretation of resource contents during exploratory search, and the semantic priming of existing tags in turn influences future tag choices. The model predicts that (1) users who can see tags created by others tend to create tags that are semantically similar to these existing tags, demonstrating the social influence of tag choices; and (2) users who have similar information goals tend to create tags that are semantically similar, but this effect is mediated by the semantic representation and interpretation of social tags. Results from the experiment comparing tagging behavior between a social group (where participants can see tags created by others) and a nominal group (where participants cannot see tags created by others) confirmed these predictions. The current results highlight the critical role of human semantic representations and interpretation processes in the analysis of large-scale social information systems. The model implies that analysis at both the individual and social levels are important for understanding the active, dynamic processes between human knowledge structures and external folksonomies. Implications on how social tagging systems can facilitate exploratory search, interactive information retrievals, knowledge exchange, and other higher-level cognitive and learning activities are discussed.
© All rights reserved Fu et al. and/or ACM Press
Chin, Jessie, Fu, Wai-Tat and Kannampallil, Thomas (2009): Adaptive information search: age-dependent interactions between cognitive profiles and strategies. In: Proceedings of ACM CHI 2009 Conference on Human Factors in Computing Systems 2009. pp. 1683-1692.
Previous research has shown that older adults performed worse in web search tasks, and attributed poorer performance to a decline in their cognitive abilities. We conducted a study involving younger and older adults to compare their web search behavior and performance in ill-defined and well-defined information tasks using a health information website. In ill-defined tasks, only a general description about information needs was given, while in well-defined tasks, information needs as well as the specific target information were given. We found that older adults performed worse than younger adults in well-defined tasks, but the reverse was true in ill-defined tasks. Older adults compensated for their lower cognitive abilities by adopting a top-down knowledge-driven strategy to achieve the same level of performance in the ill-defined tasks. Indeed, path models showed that cognitive abilities, health literacy, and knowledge influenced search strategies adopted by older and younger adults. Design implications are also discussed.
© All rights reserved Chin et al. and/or ACM Press
Moon, J. Michelle and Fu, Wai-Tat (2009): Effects of spatial locations and luminance on finding and re-finding information in a desktop environment. In: Proceedings of ACM CHI 2009 Conference on Human Factors in Computing Systems 2009. pp. 3365-3370.
We studied how spatial locations and luminance affect finding and re-finding information in a desktop environment. In an experiment conducted with computer icons, fixed locations led to more frequent accesses to icons while change of luminance led to worse recall of icon titles and locations. Results are consistent with the notion that information search behavior is adaptive to the cost-benefit structure of the interface, and search strategies are adaptive to different external representations of icons. Results also suggest that both external representations and human information processes are critical in determining the effectiveness of different GUI designs.
© All rights reserved Moon and Fu and/or ACM Press
Fu, Wai-Tat (2008): The microstructures of social tagging: a rational model. In: Proceedings of ACM CSCW08 Conference on Computer-Supported Cooperative Work 2008. pp. 229-238.
This article presents a rational model developed under the distributed cognition framework that explains how social tags influence knowledge acquisition and adaptation in exploratory ill-defined information tasks. The model provides integrated predictions on the interactions among link selections, use and creation of tags, and the formation of mental categories. The model shows that the quality of tags not only influences search efficiency, but also the quality of mental categories formed during exploratory search. In addition, the model shows that aggregate regularities can be explained by microstructures of behavior that emerged from the adaptive assimilation of concepts and categories of multiple users through the social tagging system. The model has important implications on how collaborative systems could influence higher-level cognitive activities.
© All rights reserved Fu and/or ACM Press
Fu, Wai-Tat and Pirolli, Peter (2007): SNIF-ACT: A Cognitive Model of User Navigation on the World Wide Web. In Human-Computer Interaction, 22 (4) pp. 355-412.
We describe the development of a computational cognitive model that explains navigation behavior on the World Wide Web. The model, called SNIF-ACT (Scent-based Navigation and Information Foraging in the ACT cognitive architecture), is motivated by Information Foraging Theory (IFT), which quantifies the perceived relevance of a Web link to a user's goal by a spreading activation mechanism. The model assumes that users evaluate links on a Web page sequentially and decide to click on a link or to go back to the previous page by a Bayesian satisficing model (BSM) that adaptively evaluates and selects actions based on a combination of previous and current assessments of the relevance of link texts to information goals. SNIF-ACT 1.0 utilizes the measure of utility, called information scent, derived from IFT to predict rankings of links on different Web pages. The model was tested against a detailed set of protocol data collected from 8 participants as they engaged in two information-seeking tasks using the World Wide Web. The model provided a good match to participants' link selections. In SNIF-ACT 2.0, we included the adaptive link selection mechanism from the BSM that sequentially evaluates links on a Web page. The mechanism allowed the model to dynamically build up the aspiration levels of actions in a satisficing process (e.g., to follow a link or leave a Web site) as it sequential assessed link texts on a Web page. The dynamic mechanism provides an integrated account of how and when users decide to click on a link or leave a page based on the sequential, ongoing experiences with the link context on current and previous Web pages. SNIF-ACT 2.0 was validated on a data set obtained from 74 subjects. Monte Carlo simulations of the model showed that SNIF-ACT 2.0 provided better fits to human data than SNIF-ACT 1.0 and a Position model that used position of links on a Web page to decide which link to select. We conclude that the combination of the IFT and the BSM provides a good description of user-Web interaction. Practical implications of the model are discussed.
© All rights reserved Fu and Pirolli and/or Taylor and Francis
Fu, Wai-Tat, Bothell, Daniel, Douglass, Scott, Haimson, Craig, Sohn, Myeong-Ho and Anderson, John (2006): Toward a real-time model-based training system. In Interacting with Computers, 18 (6) pp. 1215-1241.
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.
© All rights reserved Fu et al. and/or Elsevier Science
Gray, Wayne D., Sims, Chris R., Fu, Wai-Tat and Schoelles, Michael J. (2006): The soft constraints hypothesis: A rational analysis approach to resource allocation for interactive behavior. In Psychological Review, 113 (3) pp. 461-482.
Soft constraints hypothesis (SCH) is a rational analysis approach that holds that the mixture of perceptual-motor and cognitive resources allocated for interactive behavior is adjusted based on temporal cost-benefit tradeoffs. Alternative approaches maintain that cognitive resources are in some sense protected or conserved in that greater amounts of perceptual-motor effort will be expended to conserve lesser amounts of cognitive effort. One alternative, the minimum memory hypothesis (MMH), holds that people favor strategies that minimize the use of memory. SCH is compared with MMH across 3 experiments and with predictions of an Ideal Performer Model that uses ACT-R’s memory system in a reinforcement learning approach that maximizes expected utility by minimizing time. Model and data support the SCH view of resource allocation; at the under 1000-millisecond level of analysis, mixtures of cognitive and perceptual-motor resources are adjusted based on their cost-benefit tradeoffs for interactive behavior.
© All rights reserved Gray et al. and/or their publisher
Fu, Wai-Tat and Gray, Wayne D. (2006): Suboptimal tradeoffs in information seeking. In Cognitive Psychology, 52 (3) pp. 195-242.
Explicit information-seeking actions are needed to evaluate alternative actions in problem-solving tasks. Information-seeking costs are often traded off against the utility of information. We present three experiments that show how subjects adapt to the cost and information structures of environments in a map-navigation task. We found that subjects often stabilize at suboptimal levels of performance. A Bayesian satisficing model (BSM) is proposed and implemented in the ACT-R architecture to predict information-seeking behavior. The BSM uses a local decision rule and a global Bayesian learning mechanism to decide when to stop seeking information. The model matched the human data well, suggesting that adaptation to cost and information structures can be achieved by a simple local decision rule. The local decision rule, however, often limits exploration of the environment and leads to suboptimal performance. We propose that suboptimal performance is an emergent property of the dynamic interactions between cognition and the environment.
© All rights reserved Fu and Gray and/or their publisher
Gray, Wayne D. and Fu, Wai-Tat (2004): Soft constraints in interactive behavior: The case of ignoring perfect knowledge in-the-world for imperfect knowledge in-the-head. In Cognitive Science, 28 (3) pp. 359-382.
Constraints and dependencies among the elements of embodied cognition form patterns or microstrategies of interactive behavior. Hard constraints determine which microstrategies are possible. Soft constraints determine which of the possible microstrategies are most likely to be selected. When selection is non-deliberate or automatic the least effort microstrategy is chosen. In calculating the effort required to execute a microstrategy each of the three types of operations, memory retrieval, perception, and action, are given equal weight; that is, perceptual-motor activity does not have a privileged status with respect to memory. Soft constraints can work contrary to the designer’s intentions by making the access of perfect knowledge in-the-world more effortful than the access of imperfect knowledge in-the-head. These implications of soft constraints are tested in two experiments. In experiment 1 we varied the perceptual-motor effort of accessing knowledge in-the-world as well as the effort of retrieving items from memory. In experiment 2 we replicated one of the experiment 1 conditions to collect eye movement data. The results suggest that milliseconds matter. Soft constraints lead to a reliance on knowledge in-the-head even when the absolute difference in perceptual-motor versus memory retrieval effort is small, and even when relying on memory leads to a higher error rate and lower performance. We discuss the implications of soft constraints for routine interactive behavior, accounts of embodied cognition, and tool and interface design.
© All rights reserved Gray and Fu and/or Ablex Publishing
Fu, Wai-Tat and Gray, Wayne D. (2004): Resolving the paradox of the active user: Stable suboptimal performance in interactive tasks. In Cognitive Science, 28 (6) pp. 901-935.
This paper brings the intellectual tools of cognitive science to bear on resolving the “paradox of the active user” (Carroll&Rosson, 1987) – the persistent use of inefficient procedures in interactive tasks by experienced or even expert users when demonstrably more efficient procedures exist. The goal of this paper is to understand the roots of this paradox by finding regularities in these inefficient procedures. We examine three very different data sets. For each data set, we first satisfy ourselves that the preferred procedures used by some subjects are indeed less efficient than the recommended procedures. We then amass evidence, for each set, and conclude that when a preferred procedure is used instead of a more efficient, recommended procedure, the preferred procedure tends to have two major characteristics: (1) the preferred procedure is a well-practiced, generic procedure that is applicable either within the same task environment in different contexts or across different task environments, and (2) the preferred procedure is composed of interactive components that bring fast, incremental feedback on the external problem states. The support amassed for these characteristics leads to a new understanding of the paradox. In interactive tasks, people are biased towards the use of general procedures that start with interactive actions. These actions require much less cognitive effort as each action results in an immediate change to the external display that, in turn, cues the next action. Unfortunately for the users, the bias to use interactive unit tasks leads to a path that requires more effort in the long run. Our data suggest that interactive behavior is composed of a series of distributed choices; that is, people seldom make a once-and-for-all decision on procedures. Similar to what is observed in human choice behavior in many decision-making tasks, this series of biased selection of interactive unit tasks often leads to a stable sub-optimal level of performance.
© All rights reserved Fu and Gray and/or Ablex Publishing
Pirolli, Peter and Fu, Wai-Tat (2003): SNIF-ACT: A Model of Information Foraging on the World Wide Web. In: Brusilovsky, Peter, Corbett, Albert T. and Rosis, Fiorella De (eds.) User Modeling 2003 - 9th International Conference - UM 2003 June 22-26, 2003, Johnstown, PA, USA. pp. 45-54.
Gray, Wayne D. and Fu, Wai-Tat (2001): Ignoring Perfect Knowledge In-the-World for Imperfect Knowledge In-the-Head. In: Beaudouin-Lafon, Michel and Jacob, Robert J. K. (eds.) Proceedings of the ACM CHI 2001 Human Factors in Computing Systems Conference March 31 - April 5, 2001, Seattle, Washington, USA. pp. 112-119.
Memory can be internal or external - knowledge in-the-world or knowledge in-the-head. Making needed information available in an interface may seem the perfect alternative to relying on imperfect memory. However, the rational analysis framework (Anderson, 1990) suggests that least-effort tradeoffs may lead to imperfect performance even when perfect knowledge in-the-world is readily available. The implications of rational analysis for interactive behavior are investigated in two experiments. In experiment 1 we varied the perceptual-motor effort of accessing knowledge in-the-world as well as the cognitive effort of retrieving items from memory. In experiment 2 we replicated one of the experiment 1 conditions to collect eye movement data. The results suggest that milliseconds matter. Least-effort tradeoffs are adopted even when the absolute difference in effort between a perceptual-motor versus a memory strategy is small, and even when adopting a memory strategy results in a higher error rate and lower performance.
© All rights reserved Gray and Fu and/or ACM Press
Show list on your website
Join the design elite and advance:
Changes to this page (author)23 Nov 2012: Modified03 Apr 2012: Modified
16 Jan 2011: Modified
16 Jan 2011: Modified
16 Jan 2011: Modified
03 Nov 2010: Modified
03 Nov 2010: Modified
03 Nov 2010: Modified
02 Nov 2010: Modified
02 Nov 2010: Modified
02 Nov 2010: Modified
02 Nov 2010: Modified
26 Jun 2009: Modified
05 Jun 2009: Modified
30 May 2009: Modified
09 May 2009: Modified
09 May 2009: Modified
07 Apr 2009: Modified
12 May 2008: Modified
12 Aug 2007: Added
12 Aug 2007: Added
12 Aug 2007: Added
12 Aug 2007: Added
08 Aug 2007: Added
27 Jun 2007: Modified
28 Apr 2003: Added
Page maintainer: The Editorial Team