Preface; Part I. Introduction: 1. Process tracing: from philosophical roots to best practices Andrew Bennett and Jeffrey T. Checkel; Part II. Process Tracing in Action: 2. Process tracing the effects of ideas Alan M. Jacobs; 3. Mechanisms, process, and the study of international institutions Jeffrey T. Checkel; 4. Efficient process tracing: analyzing the causal mechanisms of European integration Frank Schimmelfennig; 5. What makes process tracing good? Causal mechanisms, causal inference, and the completeness standard in comparative politics David Waldner; 6. Explaining the Cold War's end: process tracing all the way down? Matthew Evangelista; 7. Process tracing, causal inference, and civil war Jason Lyall; Part III. Extensions, Controversies, and Conclusions: 8. Improving process tracing: the case of multi-method research Thad Dunning; 9. Practice tracing Vincent Pouliot; 10. Beyond metaphors: standards, theory, and the 'where next' for process tracing Jeffrey T. Checkel and Andrew Bennett; Appendix. Disciplining our conjectures: systematizing process tracing with Bayesian analysis.