A hypothesis of human motivation that holds that behavior is caused by felt needs, that the strength of the motivation is related to the perceived value of the results of the behavior, and if the person feels that the desired results are probable. The three additional characteristics: 1. the total value of the reward is determined by both the intrinsic and extrinsic needs of the person at the time the behavior is performed; 2. the effectiveness of the behavior is related to the person’s perception of what is required to accomplish the task and his or her ability to perform it; and 3. the person’s desire to perform a task is driven by his or her views of the fairness of the rewards to be received once the task is complete.