The Porter - Lawler Extension of Expectancy Theory

  +----------------------------------------------------+
  |                                                    |
  v                                      Perceived     |
Value of    Abilities                    Equity of     | 
Reward     and Traits     +------------> Rewards       | 
  |            |          |                 |          |
  |            |          | +>Intrinsic<+   |          |
  v            v          | | Reward    |   v          |
  +->Effort------>Performance           +-------> Satifaction
  ^            ^          | |           |
  |            |          | +>Extrinsic<+
  |            |          |   Reward
Perceived    Role         |
Effort     Perceptions    |
Reward                    |
Probability               |
  |                       |
  +-----------------------+