The purpose of this paper is to present a methodology for understanding materials usage in primary classrooms in Sub-Saharan Africa that centers teachers’ actions and voices. The United Nation’s Sustainable Development Goal 4 focuses on improved primary education around the world. To meet this goal, many large, donor-funded interventions aim to improve education through provision of teacher’s guides and student textbooks. However, what many of these interventions lack is a systematic way to understand how and why teachers are making pedagogical decisions while using materials. There is a large body of work that seeks to understand how teachers make decisions as they teach, and the ways these decisions are influenced by their knowledge and beliefs. Drawing from this work, we describe a methodology and set of tools that uses observations and interviews to identify key decisions that teachers make in the classroom and why teachers made those decisions. We piloted and iteratively refined this methodology over the course of three studies and use examples from these studies to illustrate the methodology. By closely observing and listening to teachers, we gain insights that allow us to continually refine and improve materials to ultimately improve the quality of classroom instruction.