Factor Structure of the 10WISC-V Primary Subtests Across Four Standardization Age Groups

The Wechsler Intelligence Scale for Children-Fifth Edition (WISC-V; Wechsler 2014a) Technical and Interpretation Manual (Wechsler 2014b) dedicated only a single page to discussing the 10-subtest WISC-V primary battery across the entire 6 to 16 age range. Users are left to extrapolate the structure of the 10-subtest battery from the 16-subtest structure. Essentially, the structure of the 10-subtest WISC-V primary battery remains largely uninvestigated particularly at various points across the developmental period. Using principal axis factoring and the Schmid–Leiman orthogonalization procedure, the 10-subtest WISC-V primary structure was examined across four standardization sample age groups (ages 6–8, 9–11, 12–14, 15–16). Forced extraction of the publisher’s promoted five factors resulted in a trivial fifth factor at all ages except 15–16. At ages 6 to 14, the results suggested that the WISC-V contains the same four first-order factors as the prior WISC-IV (Verbal Comprehension, Perceptual Reasoning, Working Memory, Processing Speed; Wechsler 2003). Results suggest interpretation of the Visual Spatial and Fluid Reasoning indexes at ages 6 to 14 may be inappropriate due to the fusion of the Visual Spatial and Fluid Reasoning subtests. At ages 15–16, the five-factor structure was supported. Results also indicated that the WISC-V provides strong measurement of general intelligence and clinical interpretation should reside primarily at that level. Regardless of whether a fouror five-factor index structure is emphasized, the group factors reflecting the WISC-V indices do not account for a sufficient proportion of variance to warrant primary interpretive emphasis.