A naturalistic study investigated writing-related teacher planning and classroom activities in a combined second and third grade classroom and a sixth grade classroom. Data were collected from participant observation, teachers' reflections on classroom writing, and naturally occurring teacher and student writing samples. The study, which was based on the assumption that writing is a form of social interaction, produced a number of findings, including the following: (1) writing is a frequent part of classroom life; (2) its many forms and functions depend on classroom social contexts; (3) key classroom writing functions are writing to know oneself and others, to occupy free time, to participate in the community, and to demonstrate academic achievement; (4) teachers focus more on developing occasions for writing than on presenting discrete lessons in writing skills; (5) writing occasions often involve skills integration both with the language arts and across subject areas; and (6) occasions for writing require a wide range of teacher planning skills. (MM)