A study of low scores in Canadian children and adolescents on the Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV)

Knowing the prevalence of low neurocognitive scores for the WISC-IV Canadian normative sample (WISC-IVCDN) is an important supplement for clinical interpretation of test performance. On the WISC-IVCDN, it is uncommon for children and adolescents to have 4 or more subtest scores or 2 or more Index scores <= 9th percentile when all scores on the battery are considered simultaneously. As the level of the child's intelligence increases or the number of years of parental education increases, the prevalence of low scores decreases. These results are consistent with existing studies of the base rates of low scores in children and adolescents on pediatric cognitive batteries, including the WISC-IV American normative sample. Tables provided are ready for clinical use.