The first chapter introduces program evaluation as a robust arena of activity directed at collecting, analyzing, interpreting, and communicating information about the effectiveness of social programs undertaken for the purpose of improving social conditions. This is followed by a chapter on how to tailor evaluation to the characteristics of the program being evaluated and a chapter on the identification of issues and the formulation of questions. The latter chapter considers what makes a good evaluation question, determination of the questions on which the evaluation should focus, and the collation of evaluation questions and the setting of priorities. A chapter on the assessment of the need for a program addresses the role of evaluators in diagnosing social conditions and service needs, defining social problems, specifying the extent of the problem, defining and identifying the targets of interventions, and how to describe the nature of service needs. A chapter on expressing and assessing program theory discusses the evaluability assessment perspective, eliciting and expressing program theory, and assessing program theory. Remaining chapters discuss the monitoring of program process and performance, strategies for impact assessment, randomized designs for impact assessment, quasi-experimental impact assessments, the assessment of full-coverage programs, the measurement of efficiency, and the social context of evaluation. 269 references and author and subject indexes