Definition: Personality tests are used by psychologists for a number of different reasons such as tracking changes in personality and to diagnosing psychological problems. These tests usually take one of two forms: self-report or projective tests. Self-report personality tests are by far the most common. You've probably encountered a number of these tests online, often as informal or fun ways to learn more about different aspects of your personality.
Learn more about some of the uses and potential problems with these assessment tools in this overview of personality testing.