"In 1963 when Rogers published the first edition of Diffusion of Innovations, summarizing and evaluating research results on the spread of ideas, his literature search revealed about 500 studies ranging from "new drugs among physicians to hand tools among primitive tribes to hybrid corn among farmers." These he described and synthesized, along with unpublished research and personal discussions with American and European researchers in the area. Many of the studies involved cultures other than Western, and many were done by scholars in anthropology, sociology and related disciplines. Rogers concluded his survey with this statement: "This book is the first of two volumes. The second volume, co-authored with Shoemaker, can perhaps be written in ten or fifteen years after the leads for research suggested here have been followed and expanded upon." (Eleanor Blum, Frances G. Wilhoit: Mass media bibliography. 3rd ed. Urbana: University of Illinois Press, 1990 Nr. 362)

"The importance of the problem studied - History of its applications to various sciences and techniques - Relations between the general culture and the diffusion of innovations - Preparatory training for the work of diffusion - Attempt at classification - The role of personality in the work of diffusion - Attempt at a general theory of diffusion." (Jean-Marie Van Bol, Abdelfattah Fakhfakh: The use of mass media in the developing countries. Brussels: CIDESA, 1971 Nr. 2001, topic code 010)