This chapter provides a review of the current state of the principles, procedures, and practices within program evaluation. We address a few incisive and difficult questions about the current state of the field: (1) What are the kinds of program evaluations? (2)Why do program evaluation results often have so little impact on social policy? (3) Does program evaluation suffer from a counterproductive system of incentives? and (4) What do program evaluators actually do? We compare and contrast the merits and limitations, strengths and weaknesses, and relative progress of the two primary contemporary movements within program evaluation, Quantitative Methods and Qualitative Methods, and we propose an epistemological framework for integrating the two movements as complementary forms of investigation, each contributing to different stages in the scientific process. In the final section, we provide recommendations for systemic institutional reforms addressing identified structural problems within the real-world practice of program evaluation