A qualitative bias review of the adaptation of the WAIS-III for English-speaking South Africans

• Main Author: Aston, Susan
• Format: Others
• Language: English
• Published: Nelson Mandela Metropolitan University 2006
• Subjects: Wechsler Adult Intelligence Test > South Africa; Intelligence tests > South Africa
• Online Access: http://hdl.handle.net/10948/453; http://hdl.handle.net/10948/d1011931

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 English-speaking South Africans. However, since the publication of the South African adaptation in 2001, there has been some concern whether some bias may not still be present in the measure. Consequently, this study aimed to qualitatively explore the item content of the South African adaptation of the WAIS-III in order to identify items that might still be potentially biased with specific reference to cultural and linguistic issues. The researcher employed purposive sampling, a non-probability technique, to select psychology professionals to act as expert reviewers. The sample consisted of 20 registered psychologists, psychology lecturers and psychology interns from the predominant culture and language groups of the Eastern and Western Cape. Qualitative and quantitative data were collected by means of a Bias Review Questionnaire which consisted of fixed-choice questions, as well as sections in which specific comments could be indicated. The questionnaire was distributed to 20 selected participants who were qualified to administer psychometric measures and were registered with the Health Professionals Council of South Africa (HPCSA). Qualitative data was analysed using Tesch’s model of thematic content analysis, and five main themes relating to potential bias were identified, namely: Culture, Language, Education, Socio-economic status, and Format. The qualitative data was re-submitted to the expert review group for approval and further comment. Quantitative data obtained from the Bias Review Questionnaire was analysed by obtaining frequency counts, which were converted to percentages, per subtest and aspect reviewed. The major findings of the study were as follows: 1. Cultural bias is evident in the South African adaptation of the WAIS-III. The differential meanings ascribed to concepts, terms, phrases and words by diverse cultures impact on test performance, as does familiarity with stimulus materials used in the measure. 2. Language bias was detected against groups with English as their second or third language owing to the unfamiliar, and sometimes archaic, terms and vocabulary used in the measure. The intended meanings of the translated items are unclear and confusing for test-takers. 3. South African test-takers have experienced vastly divergent educational opportunities which impact on intelligence test performance. The measure contains potential bias against individuals from disadvantaged educational backgrounds. 4. The content of the items is not relevant to test-takers from deprived socioeconomic backgrounds that have been unable to access good-quality education. 5. Format bias was found to exist with respect to the timed tests. Cultural groups who do not value speededness are disadvantaged by the structure and format of the measure. Based on the findings of this study, certain recommendations were made. These include: 1. Additional qualitative investigation of the WAIS-III , with a view to further adaptation in an effort to eradicate bias on cultural or linguistic grounds, and 2. Conducting further Differential Item Functioning (DIF) analyses and establishing construct equivalence across cultural and linguistic groups to promote this objective. Among the contributions believed to have been made by this study are the identification of potentially biased subtests and items on the grounds of culture and language, which will facilitate possible further revision and adaptation of the measure. Additionally, the variables that were considered important influencing factors of cognitive test performance have been documented and are accessible for future research that will supplement the present study.