Guidelines for the Use of the WAIS-IV with WAIS-III Cross-Cultural Normative Indications

Abstract

The aim of this article was to provide practitioner guidelines for the use of the Wechsler Adult Intelligence Scale — 4th Edition (WAIS-IV) within the South African context, given the absence of local norms for this edition of the test. Normative indications for WAIS-III test performance (English administration), in respect of South African black African (predominantly Xhosa) first language samples (age range 19–30), demonstrate that Grade 12 and Graduate Xhosa groups with disadvantaged education were significantly lower than the US standardization by 20 to 30 IQ points. This raises the question as to whether practitioners should use the WAIS-III rather than the more clinically advanced WAIS-IV for such testees given the lack of appropriate norms. In response to this dilemma, a mechanism is presented for converting a WAIS-IV raw score test profile into a WAIS-III test profile such that it may be subjected to analysis in terms of available WAIS-III cross-cultural norms. Following this procedure, WAIS-III subtest scaled scores and index scores were calculated from WAIS-IV data for three young adult Xhosa speaking individuals with disadvantaged education. Descriptive comparisons of the original WAIS-IV scores and the derived WAIS-III scores reveal substantial equivalence across each of the three test profiles. Taking both clinical and statistical data into account, a neuropsychological analysis was elucidated in respect of one of these cases, on the basis of which a contextually coherent interpretation of a WAIS-IV brain injury test protocol using the Shuttleworth-Edwards et al. WAIS-III cross-cultural norms is achieved. While further research is warranted, it appears that for diagnostic purposes practitioners can legitimately proceed to the use of the WAIS-IV in respect of such educationally disadvantaged populations by means of cautious application of these WAIS-III local norms.