This book addresses itself to three questions which are crucial to effective social action and hence to the lives of those whom social programs are designed to improve: (1) why has so little high quality evaluative research been done? (2) what problems are involved in developing more evaluative research and using its results in policy making? and, (3) what should government and social scientists do to foster soundly conceived and executed evaluative research? The essays in the book are held to throw new light on each of these questions, but special attention is devoted to the first: that is, the conceptual, methodological, bureaucratic, political, and organizational factors that hinder sound evaluation. The essays deal not only with the complexities associated with each factor, but also with the many ways in which the factors become intertwined in practices. The book, however, does more than simply state problems; it could be described as a compendium of methods for assessing social programs. Among the topics dealt with are: testing for success and failure in social action; behavioral sciences impact-effectiveness model; issues in income maintenance experimentation; controlled field experiments as a model for evaluation; methodology of evaluating social action programs; evaluation in practice--compensatory education; evaluating Federal Manpower Programs; politics of evaluation--the case of Head Start; and, observations of the organization of social research. (Editors/RJ)