This article elaborates on the construct of contextualization, which constitutes a constructivist contextual view on learning. Principles of constructivism and contextualization are operationalized into a set of four analytical categories, that teacher and researchers can use for organizing thinking about teaching and learning mathematics. The categories are discussed and verified throughout the design and analysis of a classroom compatible learning activity, which is supposed to promote probabilistic reasoning.Suggestions for developing the operationalization are discussed and, on account of that, the article invites for future efforts, where the explanatory power of contextualization and its analytical categories are further explored.