An Heuristic Approach to Work Analysis

Abstract

Nine experienced pilots served as subjects in an experiment designed to evaluate differences between multifunction keyboards by measuring the objective performances of the subjects. In order to achieve a high degree of external (or content) validity, the test was designed to closely simulate a series of tasks that a pilot might encounter during actual flight. Subjects performed tracking tasks and used the keyboards for secondary tasks. Measurements of tracking parameters and of performance time and errors using the keyboards were taken. The results showed that no single variable consistently reflected changes in task difficulty. The observed tendency of subjects to employ different, changing strategies during the multiple task performance led to a tentative hypothesis that work was a composite of all of the parameters. A regression analysis was used to develop an equation with weighting coefficients for the parameters. The equation was found to be in agreement with subjective performance evaluations.