Review of the criterion-related validity of the WISC-III: the first five years

A review of studies comparing the WISC-III to other measures of intelligence and achievement indicates the revision is continuing to meet the standards established by its predecessor, the WISC-R. Correlations are substantial, both for measures of ability and achievement; however, compared to the WISC-R, the WISC-III Full Scale IQ tends to be about six points lower, probably reflecting the "Flynn effect" (1984). As a consequence, eligibility for programs in special education may be negatively affected.