Page 238 - Media Effects Advances in Theory and Research

9. POLITICAL COMMUNICATION EFFECTS 227

Agenda Setting. Once nearly synonymous with studying public
issues, agenda setting is increasingly recognized as a limited special case
of examining the importance of a broadly defined issue topic in the public
domain. Agenda-setting research is based on two related propositions: (a)
the media control the agenda by selecting certain broad issue topics for
prominent coverage, and (b) prominence subsequently determines which
issues are judged as important (McCombs & Shaw, 1972; McCombs,
Shaw, & Weaver, 1997). Over three decades agenda setting has inspired a
vast literature and contains substantial evidence supporting the second
proposition that public judgments of the salience (importance) of issues
follow the prominence of the media agenda. The early evidence took three
distinct forms: time-series comparisons of the national news agenda with
aggregated issue ratings from opinion polls (Funkhouser, 1973; MacKuen,
1981; McCombs & Shaw, 1972), panel studies examining the sequencing of
changes in the media agenda with corresponding changes in the issue
saliences of individual respondents (McCombs, 1977; Tipton, Haney, &
Basehart, 1975), and cross-sectional surveys comparing contrasting media
agendas with the issue saliences of their respective audiences (McLeod,
Becker, & Brynes, 1974). An ingenious series of experiments manipulating
the agenda of televised newscasts (Iyengar & Kinder, 1987) not only
strengthened the evidence but also attempted to tie agenda-setting
research to cognitive theories. A number of other investigators have
begun investigating “attribute agenda setting,” claiming that agenda set-
ting is such a robust theoretical structure that it can encompass, in addi-
tion to issue or object salience, the specific attributes of a topic and how
this influences public opinion (Ghanem, 1997).

Some additional words of caution are in order. Audience agenda-
setting research has become so well recognized that it has become almost
synonymous with powerful political effects of media. We should be care-
ful to note that agenda-setting effects are not necessarily powerful, conse-
quential, and universal. Real-world events such as wars and terrorist
attacks are more likely to command the agenda than are fluctuations in
media coverage. In terms of impact on audiences, news sources may be
far more influential than are stories under media control (Iyengar &
Kinder, 1987). Changes in issue salience, as cognitive effects, may not alter
affect and behavior. In political campaigns, for example, advancement of
an issue may not change voting preferences unless the issue is more favor-
able to one candidate than another. The power of the media to control
issue salience was undoubtedly overstated as “stunningly successful” in
its early formulation (Cohen, 1963) and, as discussed later, the agenda is
likely to influence primarily certain sectors of the public.