Magister Artium (Psychology) - MA(Psych) / There is an overwhelming concern about substance use amongst adolescents across the world, especially in low socio-economic status communities. The South African Substance Use Contextual Risk Instrument was developed to capture the contextual risk factors for adolescents in low socio-economic status South African communities. This study is part of a larger study which aimed to develop and conduct the initial validation of the instrument. In piloting the instrument, both English and isiXhosa mother tongue speakers were tested using the English version since the instrument is only available in English. The equivalence of the measure across the English and isiXhosa mother tongue speakers is however unknown. The purpose of this study is therefore to assess the scalar equivalence of the English version across the English and isiXhosa mother tongue speakers. The total sample was 674 consisting of 420 English and 247 isiXhosa language groups from low socio-economic status communities in Cape Town. The study employed the Hoteling’s T square test (to assess significant difference of means between the groups), the equality of reliabilities (to assess the significance of differences between the scale reliabilities) and the Tucker’s Phi coefficient of congruence (to assess the congruence of the construct across the two groups). In assessing the mean differences, the results revealed that there were significant mean differences, with the isiXhosa-speaking group performing significantly lower than the English-speaking group for most of the scales. Internal consistency was also generally lower for the isiXhosa group. The structural congruence revealed that there was incongruence between the two language groups for most of the scales with an exception of two of the twenty one scales. It can thus be concluded that the measure cannot be accepted as structurally equivalent across the two groups. It is clear that bias exists in the majority of the scales of the SASUCRI and that this version is thus not applicable for an isiXhosa speaking sample. The study recommends that the instrument is adapted for the isiXhosa speaking group. / National Research Foundation (NRF)

Magister Psychologiae - MPsych (Psychology) / Substance abuse is a global concern, particularly amongst adolescents. Research shows that secondary school learners in the Western Cape are susceptible to substance use due to the ease of access to and constant use of drugs and alcohol by their peers. The use of substances by adolescents has been linked to a number of negative consequences. The South African Substance Use Contextual Risk Instrument (SASUCRI) is an instrument developed for the purpose of identifying factors that lead to adolescent substance use and communities at risk of substance abuse. In the identification of these factors, appropriate interventions can be informed in terms of the areas that need to be focused on when dealing with the reduction of substance use. Two versions of the SASUCRI exist. However, in the investigation of the larger validation study, IsiXhosa mother-tongue learners were found to have responded to the English version of the SASUCRI. A sub-study to the larger study found that certain scales of the English version of the SASUCRI proved to be in-equivalent across the English and isiXhosa mother-tongue speakers. Recommendations were made for a further validation of the instrument by investigating the level of item bias within the in-equivalent scales, to determine the extent to which it measures what it was intended to measure. Using secondary data from the larger study, the current study investigated item bias on the identified inequivalent scales of the English version of the SASUCRI across the two language groups, using a differential research design and two statistical techniques (Mantel-Haenszel and logistic regression). The theoretical framework was that of Bias and Equivalence. Permission to conduct the study and use the data was granted from various institutions and people: the Western Cape Education Department and school principals, Committees at UWC, and the researcher of the larger study. Results revealed that bias was found in some of these scales which limit its ability to be used for its intended purpose. Therefore, recommendations for the adaptation of the English version were made.

Magister Psychologiae - MPsych / The purpose of the present study was to gather further external validity evidence towards the validity argument for an instrument designed to measure individual and contextual factors associated with adolescent substance use in low socio-economic status communities in the Western Cape, South Africa. The South African Substance Use Contextual Risk Instrument (SASUCRI) measures adolescents' subjective experiences of their own psycho-social and their communities' functioning. The present study uses secondary data analysis in order to further evaluate its external validity. Both content and structural evidence for the instrument has been gathered in the larger study in which the present study is located. Validity theory was used as the theoretical framework for the gathering of the different types of evidence in support of the validity argument for this instrument. The study employed non-probability purposive sampling to select schools from three education districts from which twenty-six schools were selected where the sample total was N=1959. English and Afrikaans versions of the instrument were administered to English- and Afrikaans home language, school-going adolescents, aged 12 to 21 years. All ethical standards were maintained throughout the research process. External evidence procedures were conducted using Discriminant Function Analysis (DFA) to evaluate the extent to which the instrument could discriminate between substance using and non-using adolescents. The DFA revealed that nine SASUCRI sub-scales totals can act as significant predictors to substance use among adolescents based on the predictive validity of sub-scales.