Projective tests are measures used and developed by psychologists. These tests are considered "projective" because they involve showing a picture or other ambiguous stimuli to an individual and using her projection to learn about more about her. There are distinct advantages and disadvantages to projective tests, depending both on the type of test and the purpose for which it is used.
Projective tests can be used to diagnose mental illness. The Rorschach inkblot test is one example of a projective test that does this. In this test, the individual is shown a series of 10 inkblots and asked by the interviewer to explain what he sees. The answers are interpreted by the interviewer and give him an idea of the ways in which the individual organises his thoughts. This information is used as a basis for a diagnosis. An individual with a disorganised thought process, for instance, may have a psychotic disorder such as schizophrenia.
A common criticism of projective tests is their lack of standardisation. This means that different people giving the test may administer and interpret the tests differently and, therefore, the tests will yield different results. However, some tests, such as the Rorschach and the Thematic Apperception Test (TAT), have more standardised methods of interpretation than others, such as the House-Tree-Person test or techniques such as free association and dream interpretation. Projective tests are generally considered less reliable than other standardised, objective, psychological tests.
Projective tests are use to give insight into an individual's personality. For example, the TAT is frequently used as part of a larger series of tests meant to evaluate an individual's personality. The TAT involves showing cards with pictures of people in different scenarios that the test-taker uses to create a story. The stories told by the individual, as well as the way that the stories are told, tell the interviewer about the individual's personality, particularly in the areas of interpersonal relationships and the ability to deal with psychological stress.
Projective tests have been questioned for their validity or accuracy of measure. While the purpose of projective tests is to get at subconscious content, some believe the tests simply measure content that is connected to the individual's most recent experiences, rather than their deepest subconscious desires. Similar criticisms are that projective techniques make poor diagnostic measures, since they look solely at an individual's behaviour, rather than symptoms. Since behaviours can be very different, even for people with the same diagnosis, they may not give an accurate diagnostic assessment.