First published in 1955, "Personal Influence" 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. This classic volume set the stage for all subsequent studies of the interaction of mass media and interpersonal influence in the making of everyday decisions in public affairs, fashion, movie-going, and consumer behavior. The contextualizing essay in Part One dwells on the surprising relevance of primary groups to the flow of mass communication. Peter Simonson of the University of Pittsburgh has written that "Personal Influence was perhaps the most influential book in mass communication research of the postwar era, and it remains a signal text with historic significance and ongoing reverberations...more than any other single work, it solidified what came to be known as the dominant paradigm in the field, which later researchers were compelled either to cast off or build upon." In his introduction to this fiftieth-anniversary edition, Elihu Katz discusses the theory and methodology that underlie the Decatur study and evaluates the legacy of his coauthor and mentor, Paul F. Lazarsfeld.

伊莱休·卡茨（1926— ），美籍以色列社会学家。作为一名社会学家，

他一生却致力于传播学的研究，并为传播的学的发展做出了巨大的贡献。

在其半个多世纪的学术生涯中，卡茨先后任职于美国芝加哥大学、南加

利福尼亚大学和宾夕法尼亚大学，以及以色列希伯来大学和耶路撒冷大学，

并与不同学科——包括社会学、社会心理学、政治学和传播学——的众多

学者合作。自1992年起，他受聘为美国宾夕法尼亚大学校董讲座教授，

同时兼任以色列耶路撒冷大学社会学和传播学教授及应用社会研究所所长

（现已从该大学退休），目前任教于美国宾夕法尼亚大学安那堡传播学院。

与人合著或合编超过20本著作。

保罗·F·拉扎斯菲尔德（1901—1976），美国社会学家，20世纪社会学界的

重要学者之一，是哥伦比亚大学应用社会研究所的创办者。他的研究范围

相当广泛，涉及大众传播、选举与选民心理、市场研究、民意测验、失业、

教育心理、数理社会学等领域。他对社会研究方法颇有贡献，被誉为"现代

经验社会学创始人"。不仅如此，他还提出了传播学中的"两级传播流"、

"意见领袖"等概念。他是伊莱休?卡茨的合作者兼导师。