Victor Vroom's expectancy theory proposes that individuals are motivated when they have certain expectations. It explains that people make choices based on an assessment of how much effort will lead to performance, how performance will lead to rewards, and whether those rewards are attractive. The theory involves three key relationships: 1) the relationship between effort and performance, 2) the relationship between performance and rewards, and 3) the relationship between rewards and personal goals. Vroom developed this motivation theory while a professor at Yale and it differs from other theories by focusing on outcomes rather than internal needs.