Planning and the user interface: the effects of lockout time and error recovery cost

This paper reports three experiments which, through simple user-interface manipulations, examine a prediction derived from a rational analysis of problem solving: that increasing the cost of performing a problem-solving operator will increase the level of planning during problem solving and reduce the level of action in the world. The first experiment uses the slide-jump puzzle to look at the effects of imposing an implementation cost only on the undo operator of the interface to a task. The second experiment looks at problem solving with the eight-puzzle and imposes a system lockout delay after every operator application. In line with the predictions of the rational analysis model, both experiments demonstrate how these different manipulations of implementation cost result in more planning and shorter solution lengths when the operator implementation cost is high. The final experiment again uses a manipulation of lockout time and replicates the effects within the domain of a non-puzzle-like office administration type task. © 1999 Academic Press