During the last decade, social work, along with the other helping professions, has moved toward conceptualizing practice within a social systems framework. Intrapsychic variables are still important but, increasingly, the emphasis is on the clients' intimate social network as both cause and solution of a wide range of social problems. It is now widely believed that clients' well-being is enhanced when system functioning is enhanced (Gitterman and Germain, 1976).

Most of what social workers know about social systems theory comes from the sociological literature, particularly the social action system of Talcott Parsons. Although this orientation has great heuristic value for social work practice, it has been limited in its ability to generate new practice theory because of its high level of generality. For social workers, like sociologists before them, Parsonian systems theory has proved so difficult to operationalize that the hoped-for linkages and the anticipated development of new theory from the general theory have not materialized (Pfouts and Galinsky, 1976).

The authors believe that an important movement towards clarification of system properties and relationships is currently under way in the form of social network analysis. In recent years, a number of researchers from a variety of disciplines have explored the use of social networks and the specific properties of those networks as a means of operationalizing and expanding upon our intuitive understanding of the importance of social bonds. The result of this effort is a growing body of knowledge which draws not only upon systems theory but also upon previous research in other areas such as kinship, support systems, adaptation to stress, organizational theory, and information exchange.