Work Curve

WORK CURVE, showing the fluctuation of productivity during mental labor, was established by Emil Kraepelin (E. Kraepelin). The measure of productivity consists of series of homogeneous tasks (chiefly the addition of single-digit numbers) performed every 5 minutes. The accounting of work produced in this manner over the course of two hours makes it possible to construct a work curve. The primary factors influencing the work curve in opposite directions are fatigue (Ermüdung), which gradually lowers work productivity, and practice (Übung), under the influence of which productivity increases. In addition to these two factors, according to Kraepelin, work productivity is influenced by the following constituent parts of the work curve: «habituation» (Gewöhnung), necessary for adaptation to the given type of work; «excitation» (Anregung), which increases productivity at the beginning of the work; and «volitional tension» (Willensanspannung), the effect of which is manifested chiefly at the very beginning and before the end of the work.