Examining the factor structure of the WISC-IV in clinical and normal samples: a multiple-group confirmatory factor analysis

Abstract

Objective:The aim of this study is to examine the factor structure and measurement invariance of the Wechsler Intelligence Scale for Children Fourth Edition (WISC-IV), which is used for intellectual assessment in clinical and non-clinical samples, through using the Confirmatory Factor Analysis (CFA) method. Method:The sample of the study consisted of two groups, of which 415 were clinical (those having attention deficit hyperactivity disorder, specific learning disability, and intellectual disability) and 437 were developmentally normal children without any clinical diagnosis. In order to test first-order (the correlated four-factor model) and higher-order factor structure (model including general intelligence factor) of the WISC-IV, CFA was performed separately for each group. Furthermore, multiple group CFA was also performed to examine measurement invariance across groups.Results: Findings of CFA carried out separately for the groups revealed excellent model fit indices for both the correlated firstorder and second-order structure of the WISC-IV in both sample groups. However, as a result of multiple group CFA, model fit indices and factor loadings of the clinical sample were found to be better for the correlated four-factor first-order structure compared to the non-clinical sample. Conclusion:The findings suggest that the WISC-IV index and subtest scores measure the same cognitive structure for both groups.