Higher Order, Multisample, Confirmatory Factor Analysis Of The Wechsler Intelligence Scale For Children - Fourth Edition: What Does It Measure?

The recently published fourth edition of the Wechsler Intelligence Scale for Children (WISC-IV) represents a considerable departure from previous versions of the scale. The structure of the instrument has changed, and some subtests have been added and others deleted. The technical manual for the WISC-IV provided evidence supporting this new structure, but questions about consistency of measurement across ages and the nature of the constructs measured by the test remain. This research was designed to determine whether the WISC-IV measures the same constructs across its 11-year age span and to explicate the nature of those constructs. The results suggest that the WISC-IV indeed measures consistent constructs across ages. The scoring structure of the test was not supported in these analyses, however. Comparison of theory-derived alternative models suggests a model more closely aligned with CattellHom-Carroll theory provides a better fit to the WISC-IV standardization data than does the existing WISC-IV structure. In particular, it appears that the WISC-IV measures crystallized ability (Gc), visual processing (Gv), fluid reasoning (Gf), short-term memory (Gsm), and processing speed (Gs); some abilities are well measured, others are not. We recommend that users regroup the Perceptual Reasoning tests, and Arithmetic, to better reflect the constructs measured by the WISC-IV. Specific suggestions are also provided for interpretation of WISC-IV scores. Copyright 2006 by the National Association of School Psychologists