Hierarchical analyses of the WISC and WISC-R: synthesis and clinical implications

A review of hierarchical factor solutions obtained on normal and atypical samples in twelve previous studies showed ability arrangements in agreement with Vernon's structural paradigm. A composite hierarchy synthesized from these studies includes a general intelligence (g) factor at the apex and major group factors corresponding to the verbal-educational (wed) and spatial-mechanical-practical (kim) dimensions at the subgeneral level. Verbal Comprehension (VC), Freedom from Distractibility (FD), Spatial (k) and Quasi-Specific (QS) minor group factors comprised the third level of the ability hierarchy. Four principles are suggested as guidelines for the clinical interpretation of the WISC-R.