In 1988, with funding from the U.S. Department of Education, a research team from the School of Library and Information Science at Indiana University began a study of the origin, development, and diffusion of the Public Library Association's (PLA) planning and evaluation manuals. The study was intended to add to the general understanding of the means by which information about administrative innovations is currently disseminated among the nation's small- and medium-sized public libraries. For the first part of the study, researchers used telephone interviews, supplemented by published and archival records, to produce a narrative description of PLA's development and dissemination activities, and to compare these activities to the theoretical diffusion models that are found in the general literature on change and innovation. The second part of the study consisted of a mail survey of 48 state library development agencies and a nationwide mail survey of a random sample of 626 public libraries serving populations under 50,000. Major findings indicate that library size is less directly related to adoption of the innovation than was expected. It is suggested that the diffusion of managerial innovations among small- and medium-sized libraries is largely influenced by the extent to which library directors can utilize multiple channels of access to information about innovations. (SD)