How public policies are designed and implemented has enormous real-world importance. Learning about how things worked and did not work is therefore critical if we want to improve public policies. Learning about how things work requires ‘theory-based’ evaluation methods. This course introduces participants to theory-based evaluation methods and how they can be used both in the design, monitoring and evaluation phases of public policy. In the first part of the course, we will discuss the different types of claims made across policy evaluation methods, focusing on understanding the difference between the assessment of average treatment effects using randomized controlled trials, and more processual knowledge about how things work from theory-based case studies.