Page 15 - Media Effects Advances in Theory and Research

4 McCOMBS AND REYNOLDS

influence of both television and newspapers was greatest during the
spring primaries. Using the correlation statistic, which summarizes the
degree of correspondence between the ranking of issues on the media
agenda and the ranking of those same issues on the public agenda, the
correlation during the spring primaries was .63. The possible range of
scores for the correlation statistic is from 1.0, a perfect correspondence,
to 0, no relationship, to 1.0, which represents a perfect inverse relation-
ship. Agenda-setting theory predicts a high positive correlation between
the media and public agendas.
Although election settings provide a natural laboratory in which to
study agenda-setting effects, the evidence that supports the theory is not
limited to elections. Winter and Eyal (1981) took a historical look at the
civil rights issue between 1954 and 1976 using 27 Gallup polls. Compari-
son of the trends in public opinion with the results of a content analysis of
the New York Times’ coverage of civil rights in the weeks immediately
prior to each poll yielded a correlation of .71. Similar findings about the
impact of news coverage on trends in public opinion come from an analy-
sis of 11 different issues during a 41-month period in the 1980s (Eaton,
1989). In each of these analyses, the media agenda is based on a mix of
television, newspapers, and newsmagazines, whereas the public agenda
is based on 13 Gallup polls. All but one of the correlations (the issue of
morality) was positive, although a pattern of considerable variability in
the strength of the correlations was visible. This calls attention to factors
other than media coverage that influence the public’s perception and
emphasizes that the public mind is not a blank slate waiting to be written
on by the mass media. Significant psychological and social factors that
impact the public’s daily transactions with the mass media will be dis-
cussed later in this chapter.
Agenda-setting effects have also been found outside of the United
States. In Pamplona, Spain, during the spring of 1995, comparisons of six
major concerns on the public agenda with local news coverage showed a
high degree of correspondence. The match with the dominant local daily
newspaper was .90. The correlation with the second Pamplona daily
was .72 and .66 with television news (Canel, Llamas, & Rey, 1996).
In Germany, a look at national public opinion patterns during 1986
through weekly comparisons of the public and media agendas showed
that television news coverage had a significant impact on public concern
about five issues, including the country’s energy supply (Brosius & Kep-
plinger, 1990). Early in 1986, the energy supply issue had little salience on
either the news agenda or the public agenda. But a rapid rise in May on
the news agenda was followed within a week by a similar rise on the pub-
lic agenda. Public concern, which earlier hovered at around 15% of the
population, suddenly moved into the 25 to 30% range. When news cover-