This article enters an ongoing discussion about the usefulness of different theories and different research designs in the analysis of classroom writing. Starting with questions about how students interpret the norms of writing and their own selves in school writing, it demonstrates the relevance of an ecological theory of writing, methodologically connected to in-depth case studies--double histories--of the dialogical relationship of student and teacher positionings over time. The related concepts of discourse roles and positionings are discussed in the context of the theories of Bakhtin and Mead. The writing double histories of two students and their teacher over 2 years in a Norwegian upper secondary school are presented. Analysis shows informants positioning themselves dialogically in relation to their ideas about self and the other, the social meaning of their written utterances in various school genres, and their changing interpretations of the social rules of school writing.