Cross-cultural differences in IQ test performance: extension of an existing normative database on WAIS-III test performance
- Authors: Gaylard, Emma K
- Date: 2006
- Subjects: Wechsler Adult Intelligence Scale , Wechsler Adult Intelligence Scale -- South Africa , Black people -- Education , Black people -- Social conditions , Intelligence tests -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2979 , http://hdl.handle.net/10962/d1002488 , Wechsler Adult Intelligence Scale , Wechsler Adult Intelligence Scale -- South Africa , Black people -- Education , Black people -- Social conditions , Intelligence tests -- South Africa
- Description: Prior research (Shuttleworth-Edwards et al., 2004) presented preliminary normative data for the Wechsler Adult Intelligence Scale – III (WAIS-III) for Southern Africa, stratified according to gender (female vs. male), language (black African vs. white English), level of education (matric/12+ years of education vs. Graduate/15+ years of education) and quality of education (disadvantaged – Department of Education and Training vs. advantaged - Private/Model C). IQ scores for black African language and white English Southern Africans were comparable with the United States of America (USA) standardization when level and quality of education were equitable. (‘White English’ is the term used to denote those of European descent whose first language is English). A limitation of the research was the lack of control for language for most of the black groups and particularly in the Private/Model C Graduate group, where sixty percent of the participants originated from Zimbabwe. These represented a particularly elite group whose education was equitable to that of the white participants throughout their education (i.e. at primary, secondary and tertiary level). In order to rectify the lack of homogeneity of language, all non- Xhosa first language participants were excluded from the black sample and sixteen additional Xhosa first language participants were tested on the WAIS-III. Data analyses found no significant differences between the original and new groups, except in the comparison between Mixed African language Private/Model C Graduates and the Xhosa first language Private/Model C Graduate/15+ years of education, where there was a lowering of WAIS-III subtest, index and IQ scores in the newly constituted group. This lowering in test performance is explained in that the new Xhosa first language 15+ years of education group was a less advantaged group than the original Mixed African Language Private/Model C Graduate group, as the new group generally had less advantaged primary school education and had generally studied less at a tertiary level. Overall, these results demonstrate an incremental increase in WAIS-III test performance for sample groups on a continuum of quality of education from least to most advantaged education. This was true for both verbal and non-verbal subtests.
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The effects of level and quality of education on a South African sample of English and African first language speakers, for WAIS-III digit symbol-incidental learning
- Authors: Donnelly, Martin Joseph Rhodes
- Date: 2001
- Subjects: Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2965 , http://hdl.handle.net/10962/d1002474 , Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Description: This study examined the effects of level and quality of education on WAIS-III Digit Symbol-Incidental Learning performance. The Pairing and Free Recall measures were administered to a South African sample (N = 68, age range 19-30), which was stratified for English and African language, level of education attained (Grade 12s and Graduates) and quality of education (advantaged and disadvantaged schooling). Results yielded no significant main or interaction effects between acculturation factors of level and quality of education. Normative guidelines of 13 or more pairs and 8 or more free recall symbols, appropriate to a non-clinical sample in a multicultural setting, are provided. Digit Symbol-Incidental Learning proved to be a culture-fair test, which contributes to its clinical utility as a sensitive memory screening tool.
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An investigation of male and female cognitive ability on the WAIS-III
- Authors: Muirhead, Joanne
- Date: 2000
- Subjects: Wechsler Adult Intelligence Scale , Sex differences (Psychology) , Intelligence tests -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3028 , http://hdl.handle.net/10962/d1002537 , Wechsler Adult Intelligence Scale , Sex differences (Psychology) , Intelligence tests -- South Africa
- Description: This study, which formed part of a larger research project, investigated the effect of gender on test performance on the Wechsler Adult Intelligence Scale - Third Edition (WAIS-III). The WAIS-III was administered to a sample of 68 participants in the Eastern Cape following the initiative of the Human Sciences Research Council to standardise the WAIS-III for a South African population. The participants, aged 19 to 30, were stratified according to language of origin (African or English First Language), educational attainment (matriculant or graduate), quality of education (Department of Education and Training or private/"Model C" school) and gender. Analyses of variance and two sample t tests were used to compare male and female test performance. For the total sample, no significant difference between males and females on Verbal, Performance and Full Scale IQ were found. On the factor indices, females scored marginally higher than males on Processing Speed at a level which was approaching significance (p = 0.105), but no significant differences were found. On subtest performance, females significantly outperformed males on Digit Symbol (p = 0.020). Differences which were approaching significance were found on Information (p = 0.133) in favour of males, and on Matrix Reasoning (p = 0.092) in favour of females. For subgroups of the total sample, the most significant differences in test performance were found for the African First Language private/"Model C" school cohort in favour of females. Thus the overriding implication that emerged from this research was that on this relatively highly educated sample, no significant gender differences in cognitive ability were apparent.
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The development of a WAIS-III short form for use in South Africa
- Authors: Rust, Annegret L
- Date: 2000
- Subjects: Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3047 , http://hdl.handle.net/10962/d1002556 , Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Description: The Wechsler Adult Intelligence Scale - 3rd Edition (WAIS-III) is the newest of the internationally recognised Wechsler family of intelligence tests. It has been improved in terms of its psychometric properties, neuropsychological assessment abilities and its content. This test is in the process of being standardised by the Human Sciences Research Council (HSRC) in South Africa. As the adapted South African version will be available shortly for use in the multicultural circumstances of South Africa, the application of the various aspects of this test needs to be investigated. This test is very comprehensive and thorough, however its one disadvantage is that it takes on average three hours to administer in its entirety. Thus there is a need to find ways in which to abbreviate the test for particular purposes when time is limited, for example in research, brief clinical assessments or neuropsychological screenings. The concept of abbreviating tests, including the earlier Wechsler intelligence test can be traced back to 1917, when it was asked if all the items on the Binet-Simon scale were required to give an accurate assessment of IQ (Levy, 1968). Since then there have been many short form suggestions made, with many different considerations in mind. These can be divided into two main approaches or methods. Firstly, the number of subtests of the scale can be reduced. Thus with the WAIS-III which consists of 14 subtests in total, an option is to use, for example only four of the subtests to get an estimate of a person's IQ. Secondly, the number of items in each subtest can be reduced. Thus only half the items or even only a third of the items on a subtest can be administered to get an estimate of the persons' performance on each subtest and in this way estimate their overall IQ. Both methods have been used on the WAIS and WAIS-R, although the reduction of the subtests is favoured. Both should now be validated and considered for use with the WATS-III in South Africa. Wechsler tests and their constituent subtests have been found to be differentially effected by race, education, language and socio-economic status (Kaufman, McLean & Reynolds, 1988; Nell 1999). These differences have also been found to impact on the short forms which are suggested, as certain subtests are considered to be more biased towards particular groups than others. Vocabulary and Block Design in particular bias testees who are not as westernised or acculturated towards a largely American and European culture (Kaufman, McLean & Reynolds, 1988). These differences, although often ascribed to race, language or socio-economic status can best be understood more broadly in terms of degree of acculturation (i.e. westernisation) (Shuttleworth-Jordan, 1996) and test-wiseness (Nell, 1999). In South Africa in particular, with its extreme cultural diversity these factors need to be carefully considered when developing short forms. In the present study the development of a short form appropriate to South Africa's diverse cultural circumstances will be approached, through a sample which has been stratified according to gender, first language (English vs. African), quality of schooling received (Private/Model C vs. DET) and level of education achieved (Matric vs. Graduate). Both a subtest reduction method and an item reduction method will be considered to arrive at a short form. The subtest reduction method will be considered further in an attempt to clarify which subtests would be more or less appropriate to include in a short form considering group differences. Finally the thesis will develop suggestions as to which short forms would be best for use in South Africa.
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