The National Writing Project (NWP) is the nation's premier professional development network dedicated to improving the teaching of writing. The NWP network comprises nearly 200 local sites in all 50 states, Puerto Rico, and the Virgin Islands. This report presents the results of a seven-year survey study of teachers participating in NWP summer institutes. These institutes are the core programs that support the development of NWP the teacher-consultants, classroom teachers who become the leaders of NWP programs. The study examines teachers' judgments about the quality of NWP institutes and about the benefits they, and ultimately their students, gain from participation. Further, the study presents teachers' reports on their use of classroom practices that are statistically correlated with higher achievement on the 1998 and 2002 writing assessments of the National Assessment of Educational Progress (NAEP), also known as the nation's report card, as well as teachers' assessments of the NWP institutes' influence on those practices. Examining these attributes of the summer institute experience and impact enables us to assess the prospects for these leading teachers' development of capacity to provide high quality professional development in NWP programs in schools. Teachers in NWP institutes were surveyed twice: once at the end of the summer institute and once toward the end of the subsequent school year, about 8 months after their participation. Findings reported here are from surveys of seven cohorts of NWP institute participants, from summer 2000 and school year 2002-03, through summer 2006 and school-year 2006-07, a total of 22,287 teachers. Our analysis takes a longitudinal perspective, asking whether institute quality varies or is consistent over time for different cohorts. Additionally, we compare the judgments of teachers with different characteristics-ethnic backgrounds, years of teaching experience, school levels, and subject area responsibilities-asking whether they have the same or different perspectives about the quality of the institutes and the contributions of the institutes to their classroom practice and their students' learning. Four appendices are included: (1) Participant data form and SI Survey; (2) Ten-minute follow-up questionnaire for teachers who attended a Writing Project Summer 2006 Invitational Institute; (3) Design and Methods Notes; and (4) Data Tables for Follow-up Survey Analyses. (Contains 41 figures, 16 tables and 30 footnotes.) ["Teachers' Assessments of Professional Development Quality, Value, and Benefits: Results from Seven Annual Surveys of Participants in National Writing Project Summer Institutes" was written with Kathleen Dickey, Ellen Meyer, Allison Murray, Mary Regan, and Laurie Senauke.]