"Developmental evaluation (DE) provides evaluative information and feedback to social innovators, and their funders and supporters, to inform adaptive development of change initiatives in complex dynamic environments. DE brings to innovation and adaptation the processes of asking evaluative questions, applying evaluation logic, and gathering and reporting evaluative data to inform and support the development of innovative projects, programs, initiatives, products, organizations, and/or systems change efforts with timely feedback. This book presents the current state of the art and practice of DE through 12 case exemplars. The book also answers to common questions about DE, presents a synthesis of patterns, themes, insights and lessons drawn from the case studies, and, for the first time, identifies and explains the essential guiding principles of DE"--