This document discusses various theories and models of work motivation. It begins by defining work motivation and outlining three elements: direction and focus of behavior, level of effort, and persistence of behavior. It then presents Maslow's hierarchy of needs and Herzberg's two-factor theory, distinguishing between motivational and maintenance factors. The document also introduces expectancy theory, focusing on valence, expectancy, and instrumentality. Additional models covered include the equity model, goal setting theory, reinforcement approaches in behavior modification, and Alderfer's ERG theory.