Countrywide norms declared obsolete: best practice alert for IQ testing in a multicultural context

Abstract

The International Test Commission (ITC) (2015) has set the standards for best practice in the psychometric test arena, and it is the responsibility of both test producers and the practitioners making use of those tests to be critically aware of situations that may fail to meet such standards. One such instance relates to the South African standardization of the US-based Wechsler Adult Intelligence Scale–Fourth Edition (WAIS-IVSA) that has recently been launched for clinical use in this country (Wechsler, 2014). Commensurate with the traditional mode of norming of the US-based Wechsler intelligence tests, the South African adaptation was conducted on the basis of population (i.e., countrywide) norming. There is a problem, however, in that the value of population-based norms is increasingly being called into question on scientific grounds. Many clinicians will assume that because an intelligence test standardization is “South African,” it will be a clinically relevant instrument and preferable to the US or UK version of the test for use in the country. However, this is an erroneous assumption that has been the topic of a watershed series of commentaries published recently in an international forum (Shuttleworth- Edwards, 2016; Suchy, 2016; Sunderaraman, Zahodne, & Manly, 2016; Taylor, 2016). It is important for South African clinicians to be fully briefed on the concerns raised that are now part of the scientific literature.