Construct validity of the Wechsler Intelligence Scale For Children - Fifth UK Edition: Exploratory and confirmatory factor analyses of the 16 primary and secondary subtests

There is inadequate information regarding the factor structure of the Wechsler Intelligence Scale for Children - Fifth UK Edition (WISC-V^UK ; Wechsler, 2016a, Wechsler Intelligence Scale for Children-Fifth UK Edition, Harcourt Assessment, London, UK) to guide interpretation.

The WISC-V^UK was examined using complementary exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) for all models proposed by Wechsler (2016b, Wechsler Intelligence Scale for Children-Fifth UK Edition: Administration and scoring manual, Harcourt Assessment, London, UK) as well as rival bifactor models.

The WISC-V^UK standardization sample (N = 415) correlation matrix was used in analyses due to denial of standardization sample raw data.

EFA did not support a theoretically posited fifth factor because only one subtest (Matrix Reasoning) had a salient pattern coefficient on the fifth factor. A model with four group factors and a general intelligence factor resembling the Wechsler Intelligence Scale for Children - Fourth Edition (WISC-IV; Wechsler, 2003, Wechsler Intelligence Scale for Children-Fourth Edition, Psychological Corporation, San Antonio, TX, USA) was supported by both EFA and CFA. General intelligence (g) was the dominant source of subtest variance and large omega-hierarchical coefficients supported interpretation of the Full Scale IQ (FSIQ) score. In contrast, the four group factors accounted for small portions of subtest variance and low omega-hierarchical subscale coefficients indicated that the four-factor index scores were of questionable interpretive value independent of g. Present results replicated independent assessments of the Canadian, Spanish, French, and US versions of the WISC-V (Canivez, Watkins, & Dombrowski, 2016, Psychological Assessment, 28, 975; 2017, Psychological Assessment, 29, 458; Fennollar-Cortés & Watkins, 2018, International Journal of School & Educational Psychology; Lecerf & Canivez, 2018, Psychological Assessment; Watkins, Dombrowski, & Canivez, 2018, International Journal of School and Educational Psychology).

Primary interpretation of the WISC-V^UK should be of the FSIQ as an estimate of general intelligence.