This study reports the results of a three-year longitudinal evaluation of a National Writing Project site and illustrates the value of using multiple sources of data to evaluate aspects of National Writing Project sites. We examined the immediate effects of the Summer Institute by looking at teachers’ reactions to writing process Instruction both before and after the Summer Institute. We also examined longrange effects by looking at how teachers implemented the writing process in their classrooms over an extended period following Institute participation. Results indicate that during the Summer Institute teachers moved from self-oriented concerns about the writing process to concerns about how this approach would influence students and fellow teachers. Results also indicate how attendance at the Summer Institute affected classroom practice. We conclude with implications and questions for further study.