The 1990s’ historic welfare reform legislation shifted U.S. social policy institutions from a bureaucratic, centralized mode for income transfer, to a “professional” mode aimed at complex behavioral change. The evaluation community has responded with a shift from traditional impact analyses to implementation studies that get to the heart of this more flexible structure. A Guide to Implementation Research, by Alan Werner, is the first volume to offer comprehensive, practical advice on conducting implementation studies in the context of program evaluation. The first chapter presents an introduction to implementation research and an overview of how to organize and conduct an implementation study. Chapter Two covers the variety of data needs and data collection techniques encountered in Implementation Research. Chapter Three describes how to organize the data to document program implementation and results. Chapter Four covers approaches to assess and explain program implementation. Each chapter contains multiple examples from the research literature as well as the work of professional evaluators. For students and practitioners of evaluation research, this book is a complete, concise, and essential guide.