The proportion heuristic: problem set size as a basis for performance judgments

How do people evaluate their degree of mastery over a task? A series of four studies demonstrated that a potentially irrelevant cue can have a strong influence on such evaluations. In these studies, the total amount of work given to participants (the problem set size) influenced both (a) the amount of work participants completed before feeling that they had performed well and were adequately prepared for a related future task, and (b) participants' assessments of their performance and their feelings of preparedness for a related future task. These effects occurred even when a randomization procedure was used to emphasize the arbitrary nature of the problem set size. The effects vanished, however, when participants were given extra time to evaluate their progress after completing each problem. Copyright © 2001 John Wiley & Sons, Ltd.