The terrain of inclusion studies in discussed in this paper from the perspective of policy discourses and teachers' constructions on student diversity. We start by discussing the concept of inclusion from normative and analystic perspectives. We then look at the kinds of discourses that can be found in the Finnish and Norwegian curricula, as well as teachers' interviews when they talk about their students. On this basis we analyse how the patterns of diversity and inclusion are conceived and constructed; the phenomenon of "diversity", as it is formulated in policy documents and as it is expressed in categories with which teachers operate and act upon in school; and, "diversity" in the context of inclusive practices. We draw from ethnographic studies in Finnish and Norwegian schools; both from mainstream and from special classes. (Contains 6 notes.)