Jennifer Widner is Professor of Politics and International Affairs at Princeton University and Director of Innovations for Successful Societies. Her research focuses on government performance, democratization, and constitutional design. Much of her work uses qualitative process-tracing case studies focused on institutional change, implementation, and service delivery. Michael Woolcock is Lead Social Scientist with the World Bank's Development Research Group, and an Adjunct Lecturer in Public Policy at Harvard Kennedy School. He is the coauthor of Contesting Development: Participatory Projects and Local Conflict Dynamics in Indonesia (2011) and Building State Capability: Evidence, Analysis, Action (2017). Daniel Ortega Nieto is a Senior Public Sector Specialist at The World Bank. He assisted the Global Delivery Initiative and led a team developing DeCODE, an evidence-based system that helps anticipate delivery challenges. He was an advisor to the Mexican Government and holds degrees from the LSE and Georgetown University.

'This exceptional volume brings together a set of renowned experts from the worlds of social science methods and policy evaluation to assess the state-of-the-art for case studies in international development practice. Case studies methods have for too long been viewed as being second-best by many methodologists and practitioners. This volume rectifies this, with several chapters convincingly arguing that case study methods have relative strengths in figuring out how development interventions work and under what complex, real-world conditions they can succeed. Other chapters provide practical guidance for how to use different case study methods for studying development interventions, providing many useful suggestions for researchers and evaluators.' Derek Beach, Professor, Aarhus University, and Author of Process Tracing Methods: Foundations and Guidelines

• 1. Using case studies to enhance the quality of explanation and implementation: integrating scholarship and development practice Jennifer Widner, Michael Woolcock, and Daniel Ortega Nieto; Part I. Internal and External Validity Issues in Case Study Research: 2. How to learn about causes in the single case Nancy Cartwright; 3. RCTs versus observational research: assessing the trade-offs Christopher Achen; 4. Drawing contingent generalizations from case studies Andrew Bennett; 5. Will it work here? Using case studies to generate 'key facts' about complex development programs Michael Woolcock; Part II. Ensuring High-Quality Case Studies: 6. Descriptive accuracy in interview-based case studies Jennifer Widner; 7. Selecting cases for comparative sequential analysis: novel uses for old methods Tommaso Pavone; 8. The transparency revolution in qualitative social science: implications for policy analysis Andrew Moravcsik; Part III. Putting Case Studies to Work: Applications to Development Practice: 9. Process Tracing for Program Evaluation Andrew Bennett; 10. Positive Deviance Cases: Their Value for Development Research, Policy, and Practice Melani Cammett; 11. Analytic Narratives and Case Studies; 12. Using Case Studies for Organizational Learning in Development Agencies Sarah Glavey, Oliver Haas, Claudio Santibanez, and Michael Woolcock; 13. Connecting Case Studies to Policy and Practice: Practical Lessons from Operational Experience Maria Gonzalez de Asis and Jennifer Widner.