The problem identified as the focus of this study is the absence of a scale that measures social functioning with validated norms for any population group in South Africa. The need for such an instrument is highlighted by the importance of measurement to social work practice. Descriptions and definitions of "social functioning" in social work literature are evaluated and social functioning is operationally defined. Various approaches to the measurement of social functioning and contemporary ideas concerning the measurement of marital and family life are explored. Literature pertaining to the Heimler Scale of Social Functioning (HSSF), the measurement instrument selected in this study to measure social functioning, is examined and systematized and research findings on the HSSF are reviewed. The examination of the HSSF is focussed on the reliability of the scale for three population groups in South Africa : Whites, Indians and Blacks. The HSSF was administered to client sample groups (N = 281) from three types of welfare agencies in Durban, South Africa. These welfare organisations represent the counterparts of the British welfare agencies from which samples were drawn in the original validation study of the HSSF. As English and Zulu speaking clients are included in sample groups, the HSSF had to be translated into Zulu. The questions included in the HSSF appear to be suitable in a construct that attempts to measure social functioning and the Zulu translation of the HSSF appears to be acceptable. Findings of the study show that the international norms of the HSSF cannot be applied without adjustment across racial and ethnic boundaries and certain changes to the norms for specific client groups are recommended. / Thesis (Ph.D.)-University of Natal, Durban, 1986.