Abstract
The Pygmalion, goal-setting, and need-for-achievement approaches use effort-to-performance expectancy in order to explain work motivation. The motivation to expend effort is distinguished from the motivation to choose a task. Expectancy is conceptualized both as a stable trait and as a changing state. A resolution of rival hypotheses derived from expectancy theory and the theory of achievement motivation is proposed. An integrative model posits that raising expectations and setting difficult goals are mutually reinforcing means that can boost productivity. It is argued that measuring expectancy as subjective probability of success (SPS) has impeded expectancy research Comparative quantiles and amount of output expected are proposed as alternatives to SPS.