Vroom assumes that behavior results from conscious choices between alternatives. It uses the Expectation, Instrumentation, and Valence variables to explain this:
The expectation is the belief that increased effort will lead to increased performance, if I work harder then it will be better. It is the belief that one's effort will result in achieving desired performance goals.
Instrumentality is the belief that a person will receive a reward if the performance expectation is met. That is, if I do a good job, there is something in it for me. This reward may come in the form of a pay raise, promotion, recognition or sense of accomplishment. Instrumentality is low when the reward is the same whatever the performance.
Valencia is the importance an individual attaches to rewards. Individual desires or goals can be classified by their importance (valence), representing how much that desire may or may not influence motivation according to its importance to the person. For example, if someone is primarily motivated by money, they may not value free time offers.
