Wechsler Adult Intelligence Scale

Wechsler Adult Intelligence Scale (WAIS) is a general IQ test, introduced in 1955 as a revised Wechsler-Bellevue test (1939) for use with adults over the age of 16.  The current version is WAIS-III (1997).  The full scale IQ is divided into 14 verbal and performance subtests, and yields three scores:

1. a verbal IQ
2. a performance IQ
3. a composite, single full-scale IQ score based on the combined scores.

The average full-scale IQ is 100, with a standard deviation of 15 (above and below the mean). This is the average IQ range where most adults would fall.

For persons under 16, the Wechsler Intelligence Scale for Children (WISC, 7-16 yrs) and the Wechsler Preschool and Primary Scale of Intelligence (WPPSI, 2 1/2-7 yrs) are used.

An IQ score can be obtained without the verbal section of the test since each section yields its own score.

Neuropsychologists use the WAIS-RNI (Wechsler Adult Intelligence Scale-Revised as a Neuropsychological Instrument). Each subtest score is tallied and calculated with respect to non-normal or brain-damaged norms.

A short, four-subtest, version of the battery has recently been released, allowing clinicians to form a validated estimate of verbal, performance and full scale IQ in a shorter amount of time. The Wechsler Abbreviated Scale of Intelligence (WASI) uses the vocabulary, similarities, block design and matrix reasoning subtests of the WAIS to provide an estimate of the full IQ scores.

14 subtests of the WAIS-III

Information, Comprehension, Arithmetic, Similarities/Differences, Vocabulary, Digit Span, Letter-Number Sequencing, Picture Completion, Digit Symbol – Coding, Block Design, Matrix Reasoning, Picture Arrangement, Symbol Search, and Object Assembly.  The optional post-tests include Digit Symbol - Incidental Learning and Digit Symbol - Free Recall.