Reports the results of a pioneering study conducted in Decatur, Illinois, validating Paul Lazarsfeld's serendipitous discovery that messages from the media may be further mediated by informal "opinion leaders" who intercept, interpret, and diffuse what they see and hear to the personal networks in which they are embedded.

Acknowledgments, Introduction to the Transaction Edition, Foreword, by Elmo Roper, PART ONE: THE PART PLAYED BY PEOPLE: A NEW FOCUS FOR THE STUDY OF MASS MEDIA EFFECTS, Section One: Images of the Mass Communications Process, I. Between Media and Mass, II. The Part Played by People, Section Two: Norms and Networks in the Process of Persuasion: Linking Small Group Research with Mass Media Research, III. An Essay in Convergence, IV. Norms and Small Groups: The Shared Character of Opinions and Attitudes, V. The Role of the Group in Influencing Change: Implications for Mass Media Research, VI. Interpersonal Networks: Communicating Within the Group, VII. The Group and the World Outside: Implications for Mass Media Research, PART TWO: THE FLOW OF EVERYDAY INFLUENCE IN A MIDWESTERN COMMUNITY, Section One: Locating Personal Influence, I. Criteria of Influence, II. A Technique of Confirmation, Section Two: The Impact of Personal Influence, III. The Place of Impact Analysis in the Study of Influence, IV. Searching for and Assessing the Impact of Various Influences, V. Evaluating the Impact of Various Influences, VI. The Role and Sequence of Various Influences, VII. Some Further Technical Problems, VIII. Variations in Impact, Section Three: The Flow of Personal Influence, IX. On Describing the Flow of Influence, X. Marketing Leaders, XI. Fashion Leaders, XII. Public Affairs Leaders, XIII. Movie Leaders, XIV. The Two-Step Flow of Communication, XV. A Summary of Influences and Influentials, Section Four: Technical Appendices and Commentaries on fhe Research, Appendix A. Choice of the City, Appendix B. A Guide to the Questionnaire, Appendix C. On Follow-up Interviewing and Analysis, Appendix D. On the Construction of Indices (Including a Substantive Addendum on an Index of Popular-Fiction Consumption), Bibliography, Index

Elihu Katz, Paul F. Lazarsfeld, Elmo Roper