This book explores how corpus-based methods can be used for discourse analysis, applied to the description of discourse organization. The primary goal is to bring these two analytical perspectives together: undertaking a detailed discourse analysis of each individual text, but doing so in terms that can be generalized across all texts of a corpus. The book explores two major approaches to this task: ‘top-down’ and ‘bottom-up’. In the ‘top-down’ approach, the functional components of a genre are determined first, and then all texts in a corpus are analyzed in terms of those components. In contrast, textual components emerge from the corpus analysis in the bottom-up approach, and the discourse organization of individual texts is then analyzed in terms of linguistically-defined textual categories. Both approaches are illustrated through case studies of discourse structure in particular genres: fund-raising letters, biology/biochemistry research articles, and university classroom teaching.