This study explored statistical equivalence of the adapted Xhosa and English version of the Woodcock-Muñoz Language Survey (WMLS) by investigating group differences on each subscale, in terms of mean scores, index reliability, and item characteristics for two language groups. A Convenience quota sampling technique was used to select 188 Xhosa (n = 188) and 198 English (n = 198) learners from Grades 6 and 7 living in rural and urban Eastern Cape. The WMLS Xhosa and English versions were administered to learners in their first languages. Significant mean group differences were found, but differences were not found on the reliability indices, or mean item characteristics. This pointed in the direction of statistical equivalence. However, scrutiny of the item characteristics of the individual items per subscale indicated possible problems at an item level that need to be investigated further with differential functioning analyses. Thus, stringent DIF analyses were suggested for future research on DIF items before the versions of the WMLS can be considered as equivalent.

Magister Artium - MA / In the majority of the schools in South Africa (SA), learners commence education in English. This English milieu poses a considerable challenge for English second-language speakers. In an attempt to bridge the gap between English as the main medium of instruction and the nine indigenous languages of the country and assist with the implementation of mother-tongue based bilingual education, this study focuses on the cross-validation of a monolingual English test used in the assessment of multilingual or bilingual learners in the South African context. This test, namely the Woodcock Muñoz Language Survey (WMLS), is extensively used in the United States in Additive Bilingual Education in the country. The present study is a substudy of a broader study, in which the original WMLS (American-English version) was adapted into SA English and Xhosa. For this specific sub-study, the researcher was interested in investigating the scalar equivalence of the adapted English version of the Verbal Analogies (VA) subscale of the WMLS across English first-language speakers and Xhosa first-language speakers. This was achieved by utilising differential item functioning (DIF) and construct bias statistical techniques. The Mantel-Haenszel DIF detection method was employed to detect DIF, while construct equivalence was examined by means of exploratory factor analysis (EFA) utilising an a priori two-factor structure. The Tucker's phi coefficient was used to assess the congruence of the construct across the two language groups / South Africa