Collaborative and participatory approaches to evaluation are becoming increasingly popular. To meet the needs of evaluators seeking to implement such approaches, the editor of this book, J. Bradley Cousins, and colleagues implemented a multi-phase empirical process to develop and validate a set of principles to guide collaborative approaches to evaluation. Those principles were first published in the American Journal of Evaluation. Collaborative Approaches to Evaluation: Principles in Use outlines the principles that the team developed, and then provides case studies of how these principles have been applied in practice. The case studies draw on programs in education, health, and community development, both in North America and also internationally. The book is an invaluable supplementary text for program evaluation courses where students’ projects are focused on more collaborative and participatory approaches, and it is an essential resource for practicing evaluators, and those who commission program evaluations.