a method for assessing an individual's mental aptitudes and comparing them with those of others, using numerical scores.
a measure of intelligence test performance devised by Binet; the chronological age that most typically corresponds to a given level of performance. Thus, a child who does as well as the average 8-year-old is said to have a mental age of 8.
the widely used American revision (by Terman at Stanford University) of Binet's original intelligence test.
intelligence quotient (IQ)
defined originally as the ratio of mental age (ma) to chronological age (ca) multiplied by 100 [thus, IQ = (ma/ca) x 100]. On contemporary intelligence tests, the average performance for a given age is assigned a score of 100.
mental quality consisting of the ability to learn from experience, solve problems, and use knowledge to adapt to new situations.
a statistical procedure that identifies clusters of related items (called factors) on a test; used to identify different dimensions of performance that underlie one's total score.
general intelligence (g)
a general intelligence factor that according to Spearman and others underlies specific mental abilities and is therefore measured by every task on an intelligence test.
a condition in which a person otherwise limited in mental ability has an exceptional specific skill, such as in computation or drawing.
a test designed to predict a person's future performance; aptitude is the capacity to learn.
Wechsler Adult Intelligence Scale (WAIS)
the WAIS is the most widely used intelligence test; contains verbal and performance (nonverbal) subtests.
defining meaningful scores by comparison with the performance of a pretested standardization group.
the symmetrical bell-shaped curve that describes the distribution of many physical and psychological attributes. Most scores fall near the average, and fewer and fewer scores lie near the extremes.
the extent to which a test yields consistent results, as assessed by the consistency of scores on two halves of the test, on alternate forms of the test, or on retesting.
the extent to which a test samples the behavior that is of interest (such as a driving test that samples driving tasks).
the behavior (such as future college grades) that a test (such as the SAT) is designed to predict; thus, the measure used in defining whether the test has predictive validity.
the success with which a test predicts the behavior it is designed to predict; it is assessed by computing the correlation between test scores and the criterion behavior. (Also called criterion-related validity.)
a condition of limited mental ability, indicated by an intelligence score of 70 or below and difficulty in adapting to the demands of life; varies from mild to profound.
a condition of retardation and associated physical disorders caused by an extra chromosome in one's genetic makeup.