What is (good) program theory in international development?

To better understand how interventions can make a difference, for whom and under what circumstances, it is paramount that we develop useful and realistic abstractions (“theories”) of intervention realities. In this blog, Jos Vaessen focuses on a lack of consensus on what program theory is about. Differences in terminology, a lack of clarity on the sources of theory, and a lack of understanding of (good) theory specification all contribute to this lack of consensus.