Several shortcomings of traditional diffusion research create major impediments to our understanding of the diffusion of innovations as well as to the development of effective strategies of policy intervention to facilitate diffusion. Among the criticisms of diffusion research are the selection bias of many diffusion studies and the futility of curve fitting as an adequate test of theoretical relevance. These shortcomings can be avoided by substantive and methodological changes in diffusion research. We argue that innovation attributes, together with policies associated with the diffusion of an innovation, account for significant differences in diffusion patterns. An empirical analysis of this thesis focuses on the diffusion of computer applications software in local government. This paper is part of a research project entitled "Diffusion and Adoption of Computer Applications Software in Local Governments." This project is supported by a grant to the Public Policy Research Organization and the Graduate School of Administration from the Division of Policy Research and Analysis of the National Science Foundation (PRA-76-15549). The views expressed herein are those of the researchers and should not be ascribed to the National Science Foundation. The full report of this research is forthcoming in Technological Innovation in American Local Governments: The Case of Computing (New York: Pergamon). © 1978 Elsevier Scientific Publishing Company.