Teachers who participated in invitational institutes of the National Writing Project (NWP) during summer 2005 responded to two surveys: a Client Satisfaction Survey immediately following the institutes, and a Follow-up Survey of Program Impact one year later. The two surveys together assess the quality and usefulness of the institutes for participants, the knowledge and skills those participants gained, changes they made in their classroom practice as a result of the institutes, and the benefits they believe their students are gaining from their having participated in the institutes. Results indicate that NWP institutes promote teacher learning and lead to increased use of effective classroom practices. The publication was written with the assistance of Laurie Senauke. (Contains 12 footnotes, 8 figures and 3 tables.)