This paper presents an approach to analyzing classroom talk that sheds light on the intellectual work of the classroom. The analysis system extends the theoretical construct of preference organization from conversational analysis to the study of a whole-class, teaching-learning interaction in a ninth-grade English classroom, during which an expert teacher helps his students prepare to write a character sketch. The analysis reveals the underlying intellectual structure of the interaction, including the teacher's pedagogical goals, the cognitive skills required for successful student participation in the activity, and the strategies students apply to the task. By using conversational structure as a cue to the content of the lesson, the analysis reveals what students stand to learn. Two tables and one figure of data are included; the transcript of the classroom discourse analyzed is attached. (Contains 66 references.) (Author/RS)