Empiricism provides the backbone of knowledge creation within social science disciplines (e.g., psychology, sociology) and applied domains of study (e.g., education, administration) alike. Yet, relative to such domains of inquiry, comparatively little empirical research on evaluation has occurred, and the research knowledge base been infrequently synthesized and integrated to influence theory and practice. The proposed book aims to fill this void with regard to participatory evaluation, a set of collaborative approaches to evaluation that is receiving considerable attention of late, including a growing body of empirical studies. The authors begin in Part 1 with the delineation of a widely known and familiar conceptual framework for participatory evaluation. They then use the framework in Part 2 as a guide to conducting an extensive review of the extant empirical knowledge base in participatory evaluation, culminating in a thematic analysis of what we know about the approach. In Part 3 the authors focus on methodological considerations of doing research on participatory evaluation through a critique of existing studies and an explication of design choices drawn from their own research program. The book concludes in Part 4 with implications for moving the field forward in terms of important research questions, methodological direction and evaluation practice. This book will be of central interest to evaluation theorists and to those who choose to conduct research on evaluation; appeal will be conceptual and methodological. It will provide excellent supplementary reading for graduate students, many of whom seek to develop empirical studies on evaluation as part of their graduate programs. Rife with examples of participatory evaluation in practice, and practical implications, the book will also benefit evaluation practitioners with an interest in evaluation capacity building and participatory and collaborative approaches to practice.