Sampling Procedure
For the survey, the South African population of persons 18 years and older was stratified according to:
Province (Western Cape, Eastern Cape, Northern Cape, Orange Free State, Natal/KwaZulu, Eastern Transvaal, PWV, North Western Province, Northern Transvaal)
Socio-economic classification:
Rural areas in former self-governing and TBVC states
Squatter areas in former non-white urban (metro and non- metro areas)
Hostels and hotels
Former urban areas for coloureds
Former urban areas for a Asians
Former urban areas for blacks
Former urban (non- metro) areas for whites
Former urban (metro) areas for whites
Rural areas, excluding the former self-governing and TBVC states
The sample allocation to these strata was done roughly proportional to the adjusted 1991 populatio n census figures with a few exceptions, among which was to ensure a minimal provincial total of 120. Multistage stratified cluster (probability) sampling was used to draw the respondents with the adjusted 1991 population census figures as measure of size. Census enumerator areas and similar areas were used as the clusters in the pen-ultimate sampling stage, from which an equal number, viz. one or two by four households were drawn. All clusters were drawn with probability proportional to size, whilst households were drawn from the final clusters with equal probability (systematically). Respondents were drawn at random from qualifying household members. In addition, population of live-in domestic workers was sampled in relation to their residence in already drawn households.
Weighting
The sample design allocation per population group was not proportional to the population figures as given in the adjusted 1991 census figures as well as updated figures for certain areas such as the former TBVC states. The population total for each region and socioeconomic category was divided by the actual realisation in the particular cell. The figure derived is the pre-weight that was used. The data was weighted for the age group 18 years and older, in other words, the population that qualified as respondents.
The aim of the factor weighting was to correct the disproportions which were incorporated in the sample design (minimum number of 120 respondents per province, over-sampled population of Asians) and the only weighting targets were stratification variables: ‘province’ and ‘socio-economic category’.