This document consists of a program description (including evidence of effectiveness) submitted by the developing institution to the Program Effectiveness Panel (PEP), formerly the Joint Dissemination Review Panel (JDRP), for validation as an exemplary program and eligibility for National Diffusion Network (NDN) funding as a "Developer-Demonstrator" project. IMPACT II is a model program that incorporates a process proven to disseminate teacher-developed, classroom-based programs for the improvement of instruction. The program identifies innovative teachers, awards grants to support the dissemination and adaptation of their exemplary projects, and establishes teacher networks. In order to facilitate the dissemination of good projects, the program sponsors workshops and conferences, annual catalogs, and interschool visits. The IMPACT II national organization provides technical assistance and dissemination guidelines to school systems interested in implementing the model. In a 3-year evaluation of the program experience in public and private schools, IMPACT II teachers were found, on average, to talk with 43 others about their ideas for better teaching. Participating teachers, compared to others, were more likely to use innovative ideas, and new methods of presentation, grouping and classroom management. Participants reported increases in self-esteem and greater professional commitment. The results were stable over time and across three sites. (JD)