Effort control and judgments

Abstract

This study examined the interrelationships among judgments of task effort, performance, and difficulty. Sixty subjects provided judgments in the form of ratings of 28 hypothetical tasks in which they might have engaged. Performance level judgments were expressed as subjective probabilities of success at the tasks. The subjective relationship between effort and performance at a task was characterized by the way such probabilities of success changed as a function of effort devoted to the task. Contrary to the hypothesis suggested by the inverted-U Yerkes—Dodson (1908) relationship, subjects generally believed performance level to increase monotonically with effort. Subjects' perceived effort—performance relationships were examined for two characteristics: (a) the maximum achievable levels of performance and (b) the degree to which performance level was seen as a positively or negatively accelerated function of effort. It is argued that these two characteristics of effort—performance functions capture important and distinct aspects of task difficulty. Indexes of these characteristics derived from subjective effort—performance functions jointly accounted for 60% of the variance in overall task difficulty ratings. Implications of the approach and results of the study for effort control and current models of motivation are discussed.