The goal setting theory is a motivational model that focuses on the process of setting goals. It is a theory that was created by Edwin Locke and Gary Latham in the 1980s. The goal setting theory has been used in many fields to improve performance and it is one of the most popular theories in psychology.

The goal-setting theory is based on three main principles:

- The performance principle, which states that people will do what they think they can do to achieve their goals

- The expectancy principle, which says that people will be motivated to perform an activity if they believe they will succeed at it

- The instrumentality principle, which says that people are more likely to work hard if they believe that their efforts will lead to a desired outcome.

Goal setting theory is a motivational theory in psychology that deals with the process of setting and attempting to achieve goals.

The goal-setting theory was first introduced by Edwin Locke, a professor of management at the University of Southern California. It proposes that when there is a discrepancy between what one wants and what one has, one's motivation to reduce that discrepancy increases. In other words, people are motivated to achieve goals because they want what they don't have, not because they want more of what they already have.

The goal-setting theory has been used in many domains such as education, sports, business and clinical psychology.