Research conducted during the last few years has investigated the relationship between these personality variables and several dependent variables including performance on classroom tests, preference for certain degrees of risk, estimation of future success, persistence at tasks, and several others. The extent of these findings has seemed substantial enough to warrant the use of achievement-motivation variables as predictors of performance in applied as well as laboratory studies. This is not to imply that the reported findings are always consistent or that significant differences are always discovered. Since the theory of achievement motivation does appear to be of considerable potential use in several areas, any attempt at clarification would seem to be a contribution in a practical as well as a theoretical sense. In this paper one such attempt will be reviewed and data will be presented that seem to clarify some of the inconsistencies in the literature. In particular, control-of-reinforcement theory, originally devised by Julian Rotter, will be reviewed and an attempt will be made to show how a consideration of this theory along with the theory of achievement motivation can aid in understanding the conditions under which both theories apply.