Replication of the Wechsler Intelligence Scale for Children--Third Edition Four-Factor Model in the Canadian Normative Sample.

Confirmatory factor analyses of the Wechsler Intelligence Scale for Children-Third Edition (WISC-III ; D. Wechsler, 1991) subtests, using the Canadian normative sample, were conducted to verify the 4-factor model identified for WISC-III in the U.S. normative sample. Because the items and test materials for WISC-III were identical in both samples, this study focused on replication of the factor model across national samples. The Canadian normative sample (N = 1,100) was a stratified random sample of Canadian children, ages 6 to 16. Results for the Canadian sample paralleled those found in the U.S. sample (N = 2,200) and confirmed the presence of the 4 factors previously identified (Verbal Comprehension, Perceptual Organization, Processing Speed, and Freedom From Distractibility). This article also provides justification for the scoring and clinical use of WISC-III factor indexes.