Fairweather and ESID: contemporary impact and a legacy for the twenty-first century.

This paper illustrates how the articles in this special issue demonstrate the central values, research, and action principles inherent in Fairweather's ESID model. The programs described in these articles address earlier social problems in new forms (e.g., previously, institutionalized mentally ill patients and now, the homeless mentally ill) and new issues (e.g., HIV prevention). Dissemination of innovative programs is abundant, but only recently has research begun in earnest to study the critical processes of dissemination. Moreover, Fairweather has pointed us in important, but yet unrealized directions for how to pursue a theory of social change on the basis of ecological concepts, innovative research methods and data analytic techniques, and salient change agent behaviors and principles.