Policy studies or policy analyses can be broadly defined as the study of the nature, causes, and effects of alternative public policies. There is a general agreement on some of the basic aspects of what each social science may have to contribute to policy causal analysis and policy evaluation analysis. Sociology has developed a substantial amount of factual knowledge and theory in broad fields which can be helpful in understanding the effects of alternative policies and the behavior of policymakers and appliers. The field of economics has developed the most sophisticated mathematical models for synthesizing normative and empirical premises to analyze policy recommendations. Economic reasoning can often lead to deductive models which enable predictions about the effects of some policies before they are adopted. Psychology has done much to develop techniques of statistical inference, cross-tabulation, survey research, and multivariate analyses, especially with imprecise variables. Such methodologies have been used to evaluate the effects of alternative public policies. Anthropology, geography, and history provide a broader perspective than the other social sciences and can help to keep policy analysis within a larger perspective. Philosophy, especially normative social philosophy, tends to give policy studies direction in regard to what they are seeking to achieve. As a social science, the legal field is close to the heart of policy studies because virtually all policy problems are capable of at least attempted resolution by legislatures, courts, or lawmaking administrative agencies. Finally, political science is particularly relevant to the study of the causes and effects of governmental policies. A perception of the study of governmental problems as an interdisciplinary activity is needed. Eight notes accompany the text.