Brian D. Ehret

Learn More
Scaled worlds preserve certain functional relationships of a complex task environment while paring away others. The functional relationships preserved are defined by the questions of interest to the researcher. Different scaled worlds of the same task may preserve and pare away different functional relationships. In this paper we use the example of Ned to(More)
Knowledge of object locations in direct manipulation interfaces improves performance by restricting visual search. This paper explores the effects of label representativeness and practice on the learning of object locations. Results showed that as label representativeness decreased, location knowledge increased. All participants were shown to have learned(More)
How much time the user spends working on a task versus fiddling with the tool is an important aspect of usability. The concept of the ratio and distribution of tool-only operations to total operations is proposed to capture this aspect. INTRODUCTION Using a tool to perform a task ~quires the user to translate goals from a task space into subgoals and(More)
  • 1