This study of 32 public secondary school English teachers in the state of Alabama and of 477 students in these teachers' participating classes, employed teacher and student surveys and early- and late-in-course samples of timed narrative and persuasive writing. As predicted, NWP teachers wrote more extensively than comparison teachers, and the participating teachers' own active writing practice was associated with their students' achievement in writing. Less routinized organization of the classroom was associated with students' achievement in writing. Teachers' higher level of ongoing involvement in NWP professional development activities predicted their students' achievement on nonroutine attributes of writing. Complete analysis of the reliability of the scoring of student writing is appended. (Contains 12 tables, 1 figure, 6 footnotes and 2 endnotes.) [This report was funded by the Auburn University Department of Curriculum and Teaching.]