Agenda-setting theory

Agenda-setting theory describes the "ability [of the news media] to influence the salience of topics on the public agenda." That is, if a news item is covered frequently and prominently, the audience will regard the issue as more important. Agenda-setting theory was formally developed by Max McCombs and Donald Shaw in a study on the 1968 American presidential election. In the 1968 "Chapel Hill study," Combs and Shaw demonstrated a strong correlation coefficient (r > .9) between what 100 residents of Chapel Hill, North Carolina thought was the most important election issue and what the local and national news media reported was the most important issue. By comparing the salience of issues in news content with the public's perceptions of the most important election issue, McCombs and Shaw were able to determine the degree to which the media determines public opinion. Since the 1968 study, published in a 1972 edition of Public Opinion Quarterly, more than 400 studies have been published on the agenda-setting function of the mass media, and the theory continues to be regarded as relevant.

The theory of agenda-setting can be traced to the first chapter of Walter Lippmann's 1922 book, Public Opinion. In that chapter, "The World Outside And The Pictures In Our Heads," Lippmann argues that the mass media are the principal connection between events in the world and the images in the minds of the public. Without using the term "agenda-setting," Walter Lippmann was writing about what we today would call "agenda-setting." Following Lippmann, in 1963, Bernard Cohen observed that the press "may not be successful much of the time in telling people what to think, but it is stunningly successful in telling its readers what to think about. The world will look different to different people," Cohen continues, "depending on the map that is drawn for them by writers, editors, and publishers of the paper they read." As early as the 1960s, Cohen had expressed the idea that later led to formalization of agenda-setting theory by McCombs and Shaw.

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