Maxwell McCombs and Jae Kook Lee
In the decades since the seminal Chapel Hill study, agenda setting has evolved into a broad theory and set of hypotheses encompassing five theoretical areas. Characterized by two major trends, all five of these areas remain active research arenas. There is a centrifugal trend, the expansion into new domains and settings far beyond the original realm of public issues. Their counterpoint is a centripetal trend in which scholars have turned their attention inward to further explication of the theory's basic concepts. Much of this work concentrates on the psychology of the agenda-setting process. This chapter examines the role of incidental learning and of moderator and mediating variables in the agenda-setting process, and the impact of agenda-setting effects at both the first and second level on the formation of attitudes and opinions and on subsequent behavior.
The media lay the foundations of public opinion through their substantial influence on the topics at the center of public attention. This agenda-setting role of the media, its influence on what the public comes to regard as the most important topics of the day, has its intellectual origins in Walter Lippmann's Public Opinion (1922). His thesis that the news media are the bridge between the vast world of public affairs and each citizen's limited perspective of that world was empirically tested ...