IQ tests measure how well a person can perform a variety of mental tasks, including fact recall, abstract reasoning, visual-spatial ability and short-term memory. The tests do not measure such characteristics as creativity, interpersonal skill or wisdom.
The "quotient" portion of IQ is actually a measure of a person's mental age in comparison to his or her chronological age. The quotient also indicates how a test-taker compares to other test-takers of the same age.
Certain IQ tests are designed specifically for children. According to the Mensa Foundation, IQ tests are not given to children before their second birthday.
The definition of normal mental aptitude can vary from test to test. The type of test a person takes can influence the IQ score by as much as 10 points.
Anyone interested in obtaining the most accurate IQ result should take the test from a psychologist or educator, according to the Mensa Foundation.