Drawing on Bernstein's notion of pedagogic culture or the "mode of being" of the school, this paper develops and uses a theoretical framework for the analysis of school organization that draws attention to specialization of instructional practice. An understanding of the ordering principles of the school emerges from the analysis, fundamentally understood as relations of power and control in the school as an organization. The paper considers how the ordering principles of the school are related to differential performance. The framework is deployed in an analysis of six primary schools located in poor communities in South Africa.