Book excerpt: Comparative case studies are an effective qualitative tool for researching the impact of policy and practice in various fields of social research, including education. Developed in response to the inadequacy of traditional case study approaches, comparative case studies are highly effective because of their ability to synthesize information across time and space. In Rethinking Case Study Research: A Comparative Approach, the authors describe, explain, and illustrate the horizontal, vertical, and transversal axes of comparative case studies in order to help readers develop their own comparative case study research designs. In six concise chapters, two experts employ geographically distinct case studies—from Tanzania to Guatemala to the U.S.—to show how this innovative approach applies to the operation of policy and practice across multiple social fields. With examples and activities from anthropology, development studies, and policy studies, this volume is written for researchers, especially graduate students, in the fields of education and the interpretive social sciences.