A study examined the effectiveness of a staff development program in the Yale (Michigan) public schools, intended to provide professional development to all elementary and secondary language arts teachers about the instruction of writing process and the evaluation of student work. Evaluation of the professional development model included teacher surveys of faculty training workshops and pre- and post-workshop opportunities for students to write. Workshops for teachers received high rankings and the school district experienced a large and significant increase in student writing opportunities. To evaluate qualitative outcomes for student writing, a field experiment was conducted using an out-of-district classroom as a control. Intercorrelations for judgments were high, and the experimental class showed greater and more significant improvement than the control. The data seem to indicate that the professional development model used had an effect on teacher and student behavior and has resulted in both quantitative and qualitative outcomes. Student opportunities to write jumped by almost threefold. Furthermore, the data indicates that the direct instruction of process writing can make a significant difference in the quality of student writing. (A copy of "Teacher Training Programs in Writing," published by the Center for Effective Communication in Andover, Massachusetts, is appended.) (HB)