Wechsler Adult Intelligence Scale-III

The Wechsler Adult Intelligence Scale-III (wais-iii) comes from a tradition of mental ability testing that began in 1939 with the publication of the Wechsler-Bellevue Intelligence Scale, Form I (W-B I). The W-B I, which was named after David Wechsler and the Bellevue Hospital where he was employed as chief psychologist, was considered a unique clinical instrument because it possessed good face validity with adolescents and adults, grouped items into subtests, and provided extensive assessment of both verbal and nonverbal abilities. The scale also utilized standard scores and deviation IQs instead of the mental age values and ratio IQs provided by contemporary tests such as the Stanford-Binet Intelligence Scale, Forms L and M.