Between-subjects expectancy theory research: A statistical review of studies predicting effort and performance.

A large number of between-Ss expectancy theory studies have correlated measures of employee motivation (force) to perform with measures of effort and performance. The results of these studies vary considerably. A statistical review of the studies was conducted to determine the extent to which the variance explained (the dependent variable) was a function of various characteristics of the effort and performance and of the force-to-perform measures (the independent variables). There were 160 observations, derived from 32 studies. With the use of multiple regression analysis it was found that variance explained in these studies was greater when (a) self-report or quantitative measures of effort and performance were used rather than evaluations of these variables by someone other than the S; (b) 10–25 outcomes were included in the force measure rather than a greater or smaller number of outcomes; (c) outcome valence was numerically scaled with positive numbers only, and the scale values were described in terms of desirability rather than importance; and (d) the force measure contained either no assessment of expectancy or an assessment that confounded expectancy and instrumentality. These variables accounted for 42% of the variance in the results obtained in the studies reviewed. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)