Validation of Taiwan WISC-IV by Using Four- and Five-Factor Interpretative Approaches

Invariance is a fundamental property of any instrument used to compare individuals from subpopulations. In empirical settings, the Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV) is frequently employed as a part of psychoeducational assessments. Implicit in this common practice is the assumption that WISC-IV scores have the same meaning for children in various subpopulations. The current WISCIV manual recommends a four-factor scoring structure, whereas the Cattell-Horn-Carroll theory-based five-factor approach recommends that WISC-IV subtests assess five, instead of four, meaningful latent broad factors under g. This study investigated the factorial invariance of both four- and five-factor approaches among large normative and mixed exceptional children samples in Taiwan. Methods: Data from two large and reliable samples were analyzed. The normative sample was part of the Taiwan WISC-IV standardization sample, which consisted of 704 children aged 9 to 16 years. The overall mean fullscale intelligent quotient (FSIQ) was 100.1 (SD = 15.2). The sample consisting of exceptional children was a heterogeneous sample that included 697 children in the special education system with various diagnoses such as intellectual disability, autism, learning disabilities, attention deficit hyperactivity disorder, and other emotional and behavioral disturbances. The mean FSIQ in this sample was 84.9 (SD = 19.3). Tests for the higher-order confirmatory factor invariance among the normative and exceptional children samples were based on an analysis of the mean and covariance structure models. Both higherorder WISC-IV four- and five-factor approaches were analyzed. Results/Findings: The results based on the multigroup mean and covariance structure analysis revealed the following: (a) Both the four- and five-factor models provided a good data fit for children in both samples, suggesting that both models provide meaningful strategies for interpreting WISC-IV scores. (b) Both models demonstrated full factorial invariance between normative and exceptional samples. (c) Arithmetic, Similarities, and Symbol Search subtests were found with cross-loadings. Conclusions/Implications: For both the four- and fivefactor approaches, the WISC-IV subtests demonstrate the same underlying theoretical latent constructs, the same strength of relationships among factors and subtests, the same validity of each first-order factor, and the same communalities, regardless of clinical status. The results support the same interpretive approach and meaningful comparisons of the WISC-IV between normative and exceptional children in Taiwan. In addition, when performance inconsistencies for subtests within the same latent ability dimension are detected, or when examiners wish to test specific hypotheses, both the main and minor sources of influence for Arithmetic, Similarities, and Symbol Search subtests may warrant consideration.