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.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:rhodes/vital:3047 |
| Date | January 2000 |
| Creators | Rust, Annegret L |
| Publisher | Rhodes University, Faculty of Humanities, Psychology |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis, Masters, MSocSc |
| Format | 167 p., pdf |
| Rights | Rust, Annegret L |
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