Profile Analysis on the WISC-IV and WAIS-III in the low intellectual range: Is it valid and reliable?

This paper examines how far it is valid to generate a profile of an individual’s cognitive abilities using the WISC-IV or WAIS-III for individuals in the low ability range. Data are presented which demonstrate that the WISC-IV and WAIS-III assessments produce different cognitive profiles, when given to the same 16-year-olds who receive special education. It is suggested that at the low IQ level, subtest and index scores may lack sufficient stability for the WISC-IV or WAIS-III to produce reliable cognitive profiles.