Assessing verbal functioning in South African school beginners from diverse socioeconomic backgrounds: A comparison between verbal working memory and vocabulary measures

ASSESSING VERBAL FUNCTIONING IN SOUTH AFRICAN SCHOOL BEGINNERS FROM DIVERSE SOCIOECONOMIC BACKGROUNDS: A COMPARISON BETWEEN VERBAL WORKING MEMORY AND VOCABULARY MEASURES Kate Cockcroft University of the Witwatersrand Email: Lauren Bloch University of the Witwatersrand Azra Moolla University of the Witwatersrand ABSTRACT This study investigated whether measures of verbal working memory are less sensitive to children’s socioeconomic background than traditional vocabulary measures. Participants were 120 school beginners, divided into high and low socioeconomic groups. The groups contained equal numbers of English firstlanguage and second-language speakers. All were being educated in English. The results suggest that socioeconomic status accounts for considerable variance in vocabulary measures, while it explains only very small amounts of variance in working memory measures. In addition, the high socioeconomic university of south africa DOI: http://dx.doi.org/10.17159/1947-9417/2016/559 Print ISSN 1682-3206 | Online 1947-9417 © 2016 The Authors Education as Change www.educationaschange.co.za Volume 20 | Number 1 | 2016 pp. 199–215 199 Cockcroft, Bloch and Moolla Assessing verbal functioning in South African school beginners group performed significantly better on the two vocabulary tests relative to the low socioeconomic group, while there were no significant differences between the groups on all but one of the four working memory tests. Working memory assessments appear to be less influenced by environmental factors and may constitute fairer forms of evaluation for children from differing socioeconomic backgrounds. As such, working memory measures may be a valuable supplement to psychoeducational assessment batteries. Keywords: psychoeducational assessment, socioeconomic status, vocabulary, working memory INTRODUCTION AND BACKGROUND One of the greatest challenges in psychoeducational assessment is the fair testing of children from diverse backgrounds. Unequal opportunities to acquire knowledge will often manifest as lowered performance in such testing situations, which may not reflect the child’s actual learning ability. The greatest source of such unequal opportunities arises from differences in socioeconomic status (SES) (Brooks-Gunn and Duncan 1997; Gottfried, Gottfried, Bathurst, Geurin and Parramore 2003). The challenge of how to provide fair assessment opportunities for socioeconomically diverse children is not confined to developing countries, but has become a universal concern as a result of globalisation and the rapid movement of previously disadvantaged individuals to urban, Western environments. In South Africa, where this study was conducted, there is a stark discrepancy between wealthy and poor, as evidenced by one of the highest Gini coefficients in the world (63.1, where 0 represents perfect equality and 100 implies perfect inequality) (The Human Development Report 2013). South African children from low SES circumstances typically attend government-funded schools infamous for inadequate curricular activities, teachers’ unprofessionalism and absenteeism (Fleisch 2008). On the other hand, children from high SES circumstances generally attend ‘former model C’ schools (which were reserved for white pupils under apartheid) or privately funded schools, and are likely to have access to stimulating home and school environments. The issue of educational systems, which differ vastly in quality (where access to quality is determined by SES), is further complicated in South Africa by language issues. Across all types of educational systems, the majority of South African children are educated in English, although this is the home language of a minority (9.6%) (Roodt 2011). In addition, the majority of professionals accessed by schoolchildren (speech therapists, occupational therapists, psychologists) speak English only and are reliant on tests that are generally only available in English (Laher and Cockcroft 2013). 200 Cockcroft, Bloch and Moolla Assessing verbal functioning in South African school beginners The first year of formal schooling is often the first time that educational difficulties become apparent and the majority of psychoeducational assessments are conducted at this point (Nores and Barnett 2010). These assessments are of critical importance for the child’s scholastic career and will determine the necessity for, as well as the type of, intervention that the child should receive. Therefore, it is vital that such assessments are a fair representation of the child’s basic learning abilities. Comprehensive psychoeducational batteries aim to evaluate development and functioning over a broad range of domains, including verbal ability, and thus most such batteries include measures of receptive and/or expressive vocabulary (Flanagan, Ortiz and Alfonso 2013). Vocabulary tests reflect the results of long-term learning and verbal exposure (often referred to as crystallised ability, Gc) in the child’s social environment and are closely linked to SES (Dang, Braeken, Ferrer and Liu 2012; Hoff and Tian 2005). Some of the possible reasons for this relationship include the quality and frequency of caregiver conversations with children, caregiver attitudes towards education and the educational value of conversing and reading with children, the availability of material resources, and differences in schooling (Adams, 1990; Bradley and Corwin 2002; Hoff 2003; Noble, Wolmetz, Ochs, Farah and McCandliss 2006). When vocabulary tests are used with school beginners from poorer and non-Western environments whose backgrounds may have limited their exposure to words and concepts, it is often difficult to distinguish typical from atypical language development (Campbell, Dollaghan, Needleman and Janosky 1997). In the search for alternative, fairer ways of evaluating language functioning, the essential proposition of the current study is that verbal working memory tests may be less sensitive to SES influences than traditional vocabulary tests, and may prove to be a useful supplement to such measures. Working memory is a key cognitive mechanism underlying children’s learning; it enables the storage and processing of information, the inhibition of irrelevant information and the performance of sequences of mental actions necessary for the achievement of goals (Baddeley 2000; St Clair Thompson, Stevens, Hunt and Bolder 2010). In addition, working memory enables visual and verbal information to be instantly accessible for problem-solving, and is closely related to fluid cognition (Gf) (that is, processing, rather than knowledge-based cognition) (Horn and Cattell 1982; Hornung, Brunner, Reuter and Martin 2011; Unsworth, Redick, Heitz, Broadway and Engel 2009). The construct of working memory has been heavily influenced by the work of Baddeley and Hitch (1974), and the model developed subsequently by Baddeley (1986; 2000). According to this model, working memory compris (...truncated)