A study examined the changing conceptions about the writing instruction of three teachers who participated in the Teachers College Writing Project. Three New York City elementary school teachers were selected from a larger sample of 10 teachers who participated in a larger study of the same project. The teachers were selected because they had incorporated at least some of the strategies of the Writing Project into their teaching. Teachers participated in interviews three times over a 2-year period. Results indicated that all three teachers changed their ideas about the teacher-student relationship, the goals and purposes of writing, and their pedagogy in ways that were consistent with the Writing Project philosophy. However, influenced by their prior experiences with writing instruction, the teachers changed in different ways and to different degrees. Findings support the effectiveness of a particular staff development project, while demonstrating differences in teachers' understandings. (Thirty references are attached.) (Author/RS)