Critically examining language bias in the South African adaptation of the WAIS-III

Abstract

In response to the growing demand for a test of cognitive ability for South African adults, the Human Sciences Research Council (HSRC) adapted the Wechsler Adult Intelligence Scales, third edition (WAIS-III) for Englishspeaking South Africans. The standardisation sample included both first and second language English speakers who were either educated largely in English or Afrikaans. The purpose of this article is to critically examine the adaptation process undertaken by the HSRC when standardising the WAIS-III for English-speaking South Africans by deliberating whether sufficient attention was paid to establishing if the measure was equivalent for various groups of English first and second language test-takers. In performing this critical examination, international test adaptation guidelines and standards, psychometric conventions, and national and international research findings were contemplated. The general conclusion reached was that the equivalence of the WAIS-III across diverse language groups has not been unequivocally established and there are indications that some bias may exist for English second language test-takers, especially if they are black or Afrikaans-speaking. Based on these conclusions, recommendations are made regarding the way forward.