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Adaptive control of thought-rational (ACT-R; J. R. Anderson & C. Lebiere, 1998) has evolved into a theory that consists of multiple modules but also explains how these modules are integrated to produce coherent cognition. The perceptual-motor modules, the goal module, and the declarative memory module are presented as examples of specialized systems in(More)
The authors describe ACT-R/perceptual-motor (ACT-R/PM), an integrated theory of cognition, perception, and action that consists of the ACT-R production system and a set of perceptual-motor modules. Each module (including cognition) is essentially serial, but modules run in parallel with one another. ACT-R/PM can model simple dual tasks such as the(More)
Systematic errors in performance are an important aspect of human behavior that have not received adequate explanation. One such systematic error is termed postcompletion error: a typical example is leaving one's card in the automatic teller after withdrawing cash. This type of error seems to occur when people have an extra step to perform in a procedure(More)
Understanding the interaction of a user with a designed device such as a GUI requires clear understanding of three components: the cognitive, perceptual and motor capabilities of the user, the task to be accomplished and the artefact used to accomplish the task. Computational modeling systems which enable serious consideration of all these constraints have(More)
Click-down (or pull-down) menus have long been a key componentof graphical user interfaces, yet we know surprisingly little abouthow users actually interact with such menus. Nilsens [8] study onmenu selection has led to the development of a number of models ofhow users perform the task [6, 21. However, the validity of thesemodels has not been empirically(More)
In the 2006 U.S. election, it was estimated that over 66 million people would be voting on direct recording electronic (DRE) systems in 34% of the nation's counties [8]. Although these computer-based voting systems have been widely adopted, they have not been empirically proven to be more usable than their predecessors. The series of studies reported here(More)
Users faced with Web sites containing many possibly relevant pages often have a decision to make about navigation: use the menu of links or use the provided site search function. Two studies were conducted to examine what users do when faced with this decision on e-commerce Web sites, and how users go about deciding which method to attempt. An exploratory(More)