Working with interviews in Process Tracing evaluation methods

In this article, we provide practical guidelines for using interviews in Process Tracing evaluation methods. Process Tracing evaluation method employs more disaggregated theories of the causal process, termed a process theory-of-change. The process theory-of-change serves as the basis for conducting and using interviews in evaluation, including in the selection of respondents and the formulation of questions. The use of interviews varies across the three different phases of data collection in Process Tracing evaluation methods: (1) an exploratory phase that develops a plausible process theory-of-change, (2) a phase for testing and revising the process theory-of-change, and (3) a phase for assessment and addressing loose ends. We present guidelines for conducting and using interviews in each phase, with a particular focus on the testing and revising phase.