The WAIS-IV measure is appropriate throughout adulthood and for use with those individuals ages 16-90:11 years of age (this is an expanded age range for adults 74-90, reflecting the increased average life expectancy). For persons under 16, the Wechsler Intelligence Scale for Children (WISC, 6-16 yrs) and the Wechsler Preschool and Primary Scale of Intelligence (WPPSI, 2 1/2-7yrs, 3mos) are used.
A short, four-subtest version of the WAIS-III battery has 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 vocabulary, similarities, block design and matrix reasoning subtests similar to those of the WAIS to provide an estimate of full scale IQ in about 30 minutes.
Intelligence tests also are used in populations with psychiatric illness or brain injury, though some regard this use as controversial. Some neuropsychologists use the technique on people suffering brain damage as it leads to links with which part of the brain has been affected, or use specific subtests in order to get an idea of the extent of the brain damage. For example, digit span may be used to get a sense of attentional difficulties. Others employ the WAIS-R NI (Wechsler Adult Intelligence Scale-Revised as a Neuropsychological Instrument), another measure published by Harcourt. Each subtest score is tallied and calculated with respect to non-normal or brain-damaged norms. As the WAIS is developed for the average, non-injured individual, separate norms were developed for appropriate comparison among similar functioning individuals.