Explorations using computer simulation to comprehend thematic apperceptive measurement of motivation

Abstract

The new theory of motivation by Atkinson and Birch (1970), based on conceptual analysis of a change in activity, has been programmed to allow computer simulation of effects of differences in motivation on the stream of operant behavior. Simulation of conditions that exist when people who differ in strength of achievement motive write imaginative stories in response to a sequence of pictures shows that construct validity does not require internal consistency as traditionally supposed. The theoretically deduced differences in total time spent imagining achieving (instead of something else) can postdict input differences in motive strength (i.e., construct validity) even when there is little or no internal consistency reliability as indicated by Cronbach's (1951) alpha computed from theoretically deduced time spent imagining achievement in response to particular pictures. This general point has already been amply documented in 25 years of productive empirical research using TATn Achievement. Now a definitive theoretical refutation of the repeated psychometric criticism of the method is provided. Those who have been moved “to dispel fantasies about fantasy-based measures of achievement motivation” (Entwistle, 1972) are invited, instead, to examine the shallow theoretical foudation of our traditional myths of measurement.