In 1974 the U.S. Office of Education (USOE) established, under the Elementary and Secondary Education Act, Title III, Section 306, a network of agencies called the National Diffusion Network. This network was designed to bring together representatives of federal, state, and local agencies to promote the exchange of successful ideas, materials, and programs. Programs that have been identified as successful and validated by the Dissemination Review Panel are made available through the network to local education agencies interested in instituting these programs in their schools. This document is the first in a series of reports to be produced in connection with an evaluation of the network by the Stanford Research Institute. Section 2 of the report chronicles the evolution of the network over the last two decades. This section details how the network incorporates experience gained through USOE's past efforts to disseminate educational innovations. Section 3 attempts to place the National Diffusion Network within the context of the literature concerning diffusion of innovations. This overview of research literature describes three major models and characteristics of three major stages of the diffusion process relevant to evaluation of the network. (Author/JM)