This paper presents a comprehensive expectancy model of motivation and its implications for adult education and training. It traces the origins of valence-instrumentality-expectancy theory from its roots in social learning theory, through its early development and classical forms, to recent, more complex models. The proposed model describes expectancy motivation as part of a larger, dynamic process which includes past experience, motivation, effort, performance, reward, and need satisfaction. This model has significant implications for the design, marketing, and delivery of adult education and training, and for improving the transfer of performance from the classroom or training session to the learners practical situation.