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

Background 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. Aims and methods 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. Sample The WISC ‐ V UK standardization sample ( N  =   415) correlation matrix was used in analyses due to denial of standardization sample raw data. Results 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 ). Conclusion Primary interpretation of the WISC ‐ V UK should be of the FSIQ as an estimate of general intelligence.