Abstract: University and college composition instructors regularly assign their students classroom group work in which the students are to “share their ideas” with each other about work they have done or will do. One rationale for such group work discussion is that students will learn from each other, and the ideas, understandings, or stylistic choices they share will enhance each student's progress toward more complete coverage of their work. In addition, the talk that occurs during group work is meant to help students to recall life experiences that they might then incorporate as narrative in later versions of their work. But what are our students actually saying as they report to each other in groups, what is their talk doing to their interaction, and how is their interaction organized? This dissertation analyzes the structures of talk and embodied interaction in student group work in university writing classrooms. Using video data of naturally occurring interactions (rather than experimental data), the dissertation draws its methodological inspiration from conversation analysis and from analytic approaches to the way talk, gesture, and other forms of embodiment join in a semiotic ecology to produce social action in the course of interaction. Students in group work “share their ideas” in highly structured ways: their “reports” are similar to “stories” in ordinary conversation; they produce ongoing evaluations of each others' ideas in precise, relevant positions; and they may produce “followup reports” that reflect and legitimize a report they have just heard. In addition, they sometimes make errors about what they are meant to be doing, but have precise and effective means of redressing such errors. In short, students in group work make effective use of a range of semiotic/interactional resources to show that they are “doing group work.”