This chapter focuses on the evaluation of policies and programs. Given the importance of causal questions, the chapter's major focus is on methods for estimating the effects of policies and programs in the context of evaluation. Topics addressed include the concept of causality, experimental and quasi‐experimental designs and analysis, including techniques for dealing with attrition and with selection bias, tests of mediation, and methods of “principled discovery”, that is, the integration of exploratory methods with subsequent tests of discoveries. Given that evaluations sometimes emphasize issues other than causal questions, this chapter attends in part to other kinds of methods that may be used for evaluation. In particular, the methods, potential, and limits of performance measurement are discussed. In addition, because evaluators may need special skills to identify the right evaluation questions, attention is given to the analysis of stakeholder needs and to a potentially useful policy analytic perspective. Finally, possible future developments in the field of evaluation are discussed, including areas of potential methodological development and challenges to be faced.