Psychological Testing When one hears the phrase "psychological testing" one might be inclined to think of a test to determine one's mental health, a test that could tell someone whether she or he was crazy or not. But psychological testing is hardly so clear-cut, nor does it deal with the highly subjective subject of sanity. Psychological tests instead measure a range of qualities and potentials, including one's aptitude for various kinds of jobs, one's IQ, one's cognitive functioning, one's ideal occupation, and one's personality type. There are also specific psychological tests for certain mental illnesses, such as depression. In this paper I will briefly describe the different types of psychological tests before addressing the concepts of validity and reliability.

All psychological tests share the basic criteria of any type of test. Tests are sets of either exercises or questions (or some combination of the two) that are used in a systematic way to evaluate or determine an individual's knowledge or skill or both. Most psychological tests are administered by psychologists who have either a PhD in psychology or a PsyD -- a doctorate in psychology. However, there are also other professionals who administer at least some psychological tests, such as therapists and career counselors. A vast range of people take psychological tests in school, at work, or as part of the clinical counseling process.

Psychologists, and other professionals, use tests (as opposed to other methods of gathering information, such as clinical interviews or naturalistic...

Many researchers believe that tests are more accurate in that test subjects may find it harder to lie in a testing situation than in other situations. Information derived from tests is also consistent in terms of being able to be measured against information derived from other test subjects (Janda, 2009, p. 29). Balanced against these advantages, the information derived from psychological tests is relatively "shallow" and lacking in details compared to information derived from clinical interviews.
Two of the primary forms of psychological tests are achievement and aptitude tests. These forms of tests are often used to determine what career or job a person is best suited to. While they share certain qualities, the two types of tests do measure different things. An achievement test is designed to measure how much an individual knows about a particular subject (such as marine biology or Latin grammar) while an aptitude test is designed to determine how well one would do in gaining expertise in an area -- such as marine biology or Latin grammar. In other words, an aptitude test measures potential (Kline, 205, pp. 37-9).

IQ -- or intelligence quotient -- tests are also commonly given, although there is considerable controversy about them (Janda, 2009, p. 19). IQ tests are intended to be tests of potential as well: Intelligence can be seen as the ability to learn, assess, analyze, and apply new knowledge. IQ tests are not meant to be tests of the knowledge that one has already…