GAI stands for General Ability Index, which is a score on the Wechsler Intelligence Scale that represents an individual's overall intellectual functioning, regardless of their performance on specific subtests. The GAI is a composite score that is derived from several subtests on the Wechsler scales, which are commonly used measures of intelligence.
The GAI is intended to provide a more reliable estimate of an individual's intellectual ability, particularly for individuals who have significant discrepancies between their verbal and performance scores on the Wechsler scales. By focusing on the subtests that best measure general intellectual ability, the GAI can provide a more accurate representation of an individual's overall intelligence.
The Wechsler Intelligence Scale consists of both verbal and performance subtests that assess various cognitive abilities such as vocabulary, reasoning, memory, and spatial ability. These subtests are combined to provide a Full-Scale IQ score, which is a general measure of intelligence. The GAI provides an alternative way of interpreting an individual's intellectual functioning that is based on a subset of subtests that are most closely related to general intelligence.