USING TIME SERIES ANALYSIS
TO MEASURE INTERMEDIA
AGENDA-SETTING INFLUENCE
IN TRADITIONAL MEDIA
AND POLITICAL BLOG NETWORKS
By Sharon Meraz
Using time series analysis to gauge intermedia agenda setting in a sample of eighteen U.S. political blogs, two elite traditional news entities,
and their eleven political newsroom blogs across three issues in 2007,
this study reveals that traditional media were unable to set political blog
agendas. Ideologically diverse political blog networks were also able to
set traditional media?s online news agenda, and, to a lesser extent, their
newsroom blog agenda. Findings point to a dilution of traditional
media?s singular agenda-setting influence and to greater interdependence between traditional media and political blogs than suggested by
hyperlink studies.
J&MC Quarterly
Vol. 88, No. 1
Spring 2011
176-194
?2011 AEJMC
176
The tense relationship between traditional media and the networked blogosphere has been a feature of the new mass media landscape since political blogs arose as a force in the aftermath of the 9/11
U.S. terrorist attacks and with the ensuing wars in Afghanistan and
Iraq.1 Traditional media entities are now facing a sea change in the
economics of news production and distribution.2 As the printed medium continues to lose ground to an online model of production and distribution,3 traditional media entities have been forced to experiment
with Web 2.0 technologies while adopting blogging4 and other social
media forms5 in an effort to draw active web publics into their news
sites.
During the 2008 presidential election, visits to some popular political blogs increased by triple-digit percentage points over readership of
those blogs in the preceding 2007 year.6 Political citizen journalism also
continued to mature: citizen blogger and Huffington Post?s OffTheBus
contributor Mayhill Fowler broke two of the more sensational campaign
stories during the runoff for the 2008 democratic presidential nomination,7 recalling previous success that top political bloggers have had in
making public officials accountable.8 Though traditional newsrooms
Sharon Meraz is an assistant professor in the Department of Communication at the
University of Illinois, Chicago.
JOURNALISM & MASS COMMUNICATION QUARTERLY
were reluctant to quote Fowler as their news source,9 newsrooms from
the New York Times to news blog sites such as ABC?s The Note and
National Journal?s BlogMeter now regularly access blogs for story leads.
These anecdotal reports suggest vibrant informational codependence
between political blogs and traditional media outlets; however, little
quantitative research has compared how issue emphasis and selection
can be used to gauge intermedia agenda-setting influence between these
two media entities.
This study works within the methodological tradition of previous studies that have adopted the time series method of Granger
causality to conduct agenda-setting analysis.10 Unlike earlier studies,
this study measures the number of unique blog posts and news articles
written on an issue as an indicator of intermedia issue agenda-setting
effects. A previous study11 revealed that political bloggers were equally
as likely to link in their blog postings to traditional media as citizen
media; however, traditional media were unwilling to link to political
blogs. Departing from the use of hyperlink analysis as a marker of source
agenda-setting relationships, this study examines how the choice to
write blog postings and/or articles about an issue, in contrast to the
viewpoints adopted on those issues, can be used as an indicator of intermedia agenda-setting influence. This study compares the quantity of
blog postings on three popular public affairs issues in 2007 through a
sample of eighteen top independent political blogs (six left-leaning, six
right-leaning, and six moderate); two elite traditional media entities;
and the latter?s eleven newsroom blogs that center on U.S. political
affairs. This study also establishes the relevancy of intermedia agendasetting theory in explicating flows of influence between both traditional
media and political blogs and among political blogs of diverse political
ideology.
Intermedia Agenda Setting. Agenda setting remains one of the
most enduring and most researched theories in mass communication
and political communication.12 The maturation of agenda-setting theory
over several decades could explain previous13 findings regarding the
leveling off of academic publications that use agenda setting as a theoretical device. Since its first appearance in 1972, agenda setting has matured
as a theory to include a second-level agenda-setting component (attribute agenda setting), a psychological component to explain individuallevel agenda-setting effects (need for orientation), an emphasis on how
the media?s agenda is shaped, and an explanation for the shared news
agenda among different media (intermedia agenda setting). Given its
endurance and maturity as a mass communication theory, it is surprising
that few researchers directly apply agenda setting, specifically intermedia agenda setting, to flows of influence that occur between traditional
media and the networked political blogosphere as well as among ideologically diverse U.S. political blogs.
Intermedia agenda setting seeks to examine how the media?s
agenda is set by sources,14 and intermedia agenda setting explains the
USING TIME SERIES ANALYSIS TO MEASURE INTERMEDIA AGENDA-SETTING INFLUENCE
Literature
Review
177
flow of influence among media entities.15 In terms of more traditional
media, the intermedia agenda-setting influence has been most evident
in situations of elite influence, such as elite newsrooms? influence on
less elite mass media entities,16 newspaper influence on television
news broadcasts,17 and online newspapers? influence on wire services.18
Television outlets have also had influence on each other?s agendas.
Other forms of influence include political advertising on television
and newspaper news19 and advertising by political candidates on traditional media agendas.20 Website agendas of political candidates and
traditional mass media agendas have also exhibited strong correlations.21
Though research on the intermedia agenda-setting relationship
between traditional media and newer, emergent media is limited, most
previous research suggests that within the United States, traditional
media institutions still have the power to set non-traditional media
agendas at the issue level. Traditional media were shown to have influence on the content of the 1996 Republican candidates? press releases as
presented on candidate websites.22 In the 2004 presidential election, traditional media also influenced the campaign blog agendas, as opposed
to influence occurring in the reverse direction.23 In the context of blogs,
one study did find blog-to-media influence at the issue level; however,
the reverse level of influence was stronger.24
Intermedia agenda-setting theory has also been applied to informational influence among non-traditional media entities. One study
found significant inter-candidate issue agenda setting during the 2004
U.S. presidential election based on candidate press releases downloaded
from the candidate websites.25 Evidence has also been found for shared
issue agendas among traditional media platforms and non-traditional
portal news outlets, such as Yahoo News and Google News. In terms of
the political blogosphere, no studies have utilized intermedia agenda
setting to explain flows of influence.26
Previous studies on informational influence and agenda sharing
within the political blogosphere have centered on gauging source influence through the analysis of hyperlink connections. Several of these
studies have shown that the political blogosphere is stratified along partisan lines. Blogs that share political ideology are more prone to link to
one another and share similar source agendas.27 These hyperlink studies
suggest that partisan affiliation strongly impacts intermedia agenda setting through source agendas.
Unlike previous studies on the political blogosphere, this study
utilizes the theory of intermedia agenda setting to gauge two levels of
influence. First, intermedia agenda setting is used to gauge the influence
of the traditional newsroom on political blogs. Second, intermedia agenda setting is used to assess the flow of influence among political blogs
of disparate political ideologies. Departing from previous studies centered in hyperlink analysis, this study examines intermedia agenda setting through time series analysis estimated by Granger causality, utilizing the quantity of unique blog postings and articles on select issues as
an indicator of intermedia agenda-setting effects.
178
JOURNALISM & MASS COMMUNICATION QUARTERLY
Before conducting specific time series tests for intermedia agenda
setting, this study will test for evidence of correlated issue agendas as a
surface marker of intermedia agenda setting. Given previous findings of
ideologically driven hyperlinking practices among partisan political
blogs,28 this study advances the following hypothesis in relation to issue
selection and emphasis on partisan blogs:
Hypotheses
and
Research
Questions
H1: Blogs that share partisan ideologies will have a
more correlated issue agenda within their blog posts than
that of ideologically disparate blogs.
With the maturation of the political blogosphere, many former
journalists are now joining the ranks of elite political bloggers.29 Though
many elite political bloggers now gain first-hand access to sources,30 most
elite traditional media entities still remain in a better structural position
to break news and conduct investigative reporting on their online news
websites due to their professional affiliation to the newsroom.31 Initiating
an intermedia agenda-setting test at the most likely level of traditional
media textual influence?online news articles?this study advances the
following intermedia agenda-setting hypothesis as it relates to issue
selection and emphasis:
H2: Traditional media?s online news articles will be
more likely to set the issue agenda of political blog postings
than the reverse relationship.
This study also predicts that traditional media?s online news agenda will have more success in influencing issue selection and emphasis
within political blog issue agendas than political blogs within their own
blog networks. This study advances the following intermedia agendasetting hypothesis:
H3: Traditional media?s online news articles will be more
likely to set the issue agenda of political blog postings than political blogs will be at setting their own blog post issue agenda.
Can independent political blogs influence issue selection and
emphasis within traditional media outlets? One study found that political blogs exert influence on traditional media?s issue agenda; however,
the greater influence was from traditional media to political blogs.32 This
study advances the following research questions:
RQ1: To what extent are political blogs successful at
setting the issue agenda in traditional media?s online news
articles?
RQ2: To what extent are political blogs successful at setting the issue agenda in traditional media?s blog postings?
USING TIME SERIES ANALYSIS TO MEASURE INTERMEDIA AGENDA-SETTING INFLUENCE
179
Due to the novelty of traditional media newsroom blogging, scholarly attention has yet to assess its agenda-setting impact on other media
agendas. Thus, this study advances the following research question:
RQ3: What role do traditional media blogs play in setting the agenda of other media entities?
These three hypotheses and three research questions were tested
through comparing the frequency of blog postings and news articles
written on three select public affairs issues in 2007 in a sample of eighteen elite political blogs across the ideological spectrum, two elite traditional media entities (the New York Times and the Washington Post), and
the latter?s eleven newsroom blogs that center on politics.
Method
180
Past studies reveal that traditional media pay close attention to the
content from political blog elites.33 Using quantitative techniques,34 the
most popular blog listings from blog aggregators/search engines
Technorati, the Truth Laid Bear, and BlogPulse were correlated in an effort
to sample elite left-leaning and right-leaning political blogs. This
process yielded the following sample of twelve blogs: The Daily Kos
(left-leaning), Crooks and Liars (left-leaning), Think Progress (left-leaning),
Talking Points Memo (left-leaning), The Huffington Post (left-leaning),
FireDogLake (left-leaning), Instapundit (right-leaning), Michelle Malkin
(right-leaning), Hot Air (right-leaning), Little Green Footballs (right-leaning), Powerline (right-leaning), and Captain?s Quarters (right-leaning).
Because of their absence from popular blog listings, it was necessary to
utilize a series of triangulation techniques35 to sample popular moderate
blogs. This resulted in the selection of Donklephant, The Moderate Voice,
The Daily Dish, The Gun Toting Liberal, Central Sanity, and The Van Der
Galien Gazette. In total, eighteen blogs were selected for analysis, with six
selected across each dominant ideological spectrum.
Previous studies have found that elite newsrooms are agenda setters for less elite news media;36 as such, the online versions of the New
York Times and the Washington Post were selected to represent the traditional media?s online news agenda. This study also examined the impact
of the newsroom?s political blogs, which included the following: The
Caucas, The Lede, and the Opinionator for the New York Times, and the
political blogs White House Watch, Bench Conference, Achenblog, Early
Warning, Think Tank Town, The Fix, On Balance, and OFF/Beat from the
Washington Post. Individual media agendas were further aggregated
into five broad ?network? agendas: the left-leaning blog network, the
right-leaning blog network, the moderate blog network, the traditional
media network, and the traditional media blog network.
Rather than hand-selecting specific issues, issues for this study
were selected based on quantity of discussion generated. The issue-rich
period of July 20, 2007, to September 30, 2007, was chosen as a good time
period for selecting popular issues, and two primary criteria ultimately
guided issue selection. Each issue needed to be bound by a definite start
JOURNALISM & MASS COMMUNICATION QUARTERLY
and end point, a factor important in measuring agenda-setting effects;
and issues needed to generate notable discussion across all blogs and
media. These criteria yielded three issues: the Alberto Gonzales hearings
on the NSA wiretapping, the Larry Craig sex scandal, and the Petraeus
report and the MoveOn ?Betray us? ad on Iraq.
Exact start and end time points for the study of each of the issues
were determined by two additional factors: summing the total amount of
unique blog posts and articles on each issue through the entire time period for a visible message burst, and ensuring that over 50% of media entities (blogs and traditional media) carried a message about the issue. The
start and end time periods in 2007 for the Gonzales NSA wiretapping testimony, the Larry Craig scandal, and the Petraeus report and the
MoveOn ?Betray us? ad on Iraq were July 24 to August 2, August 27 to
September 7, and August 15 to September 24, respectively.
The sampling frame was the entire blog and traditional media
website, while the unit of analysis was the blog post for blogs (political
blogs and traditional media blogs) and the article for traditional media?s
online website agenda. For each of the three issues, the advanced search
feature on each medium?s website was used to pull all generated content
during the time period designated for each issue?s investigation. To
ensure reliability regarding which content was counted as related to
the select issues,37 inter-coder reliability tests were conducted on a
random 10% sample of content for each issue across the media entities.
Two coders compared their selection of blog posts and/or online news
articles that qualified as posts/articles on each issue. Coders were given
specific instructions to select only blog postings or online news articles
that had (1) a headline that suggested the posting/article was about
the topic, and/or (2) a lead that centrally identified the posting/article
with the topic. Inter-coder reliability scores ranged from .94 to .98
using Krippendorff?s alpha, which accounts for chance agreement.38
Upon reaching this acceptable level of agreement, one coder completed
the selection of the remaining blog postings and articles that would
account for each media entity?s total volume of content for each issue. In
total, there were 1,422 unique blog posts (1,262 culled from the eighteen
independent blogs in this sample and 160 culled from traditional media
blog posts) and 302 traditional media?s online news articles. This count
data, aggregated at the network level (left-leaning blog agenda, rightleaning blog agenda, moderate blog agenda, traditional media agenda,
traditional media blog agenda) on an issue-by-issue basis (see Table 1),
formed the basis for correlating issue agendas (H1) and for testing causation and intermedia agenda setting using Ordinary Least Squares
(OLS) regression to estimate Granger causality (H2, H3, RQ1, RQ2, and
RQ3).
Time series analysis has long been recognized and utilized as a
robust method for determining causation in agenda-setting studies,39
including intermedia agenda-setting effects.40 It is argued that Granger
causality can provide a more accurate result than other time series methods, like ARIMA modeling,41 which are more prone to error. Applying
Granger causality analysis to this study permitted predictions of each
USING TIME SERIES ANALYSIS TO MEASURE INTERMEDIA AGENDA-SETTING INFLUENCE
181
TABLE 1
Unique Blog Posting and Article Volume on Each Issue in Five Media Networks
Media Network
Left
Moderate
Right
TMediaA
TMediaB
Craig
Issues
Gonzales
Iraq
46
39
30
19
226
102
207
73
49
123
24
20
463
139
167
Note: Due to space constraints, within Table 1, Left refers to the agenda of left-leaning blogs, Right
refers to the agenda of right-leaning blogs, TMediaA refers to the agenda of traditional media?s
online news articles, and TMediaB refers to agenda of traditional media?s blog postings.
media network?s agenda based on lagged values of its past agenda and
those of other media networks.
Using OLS regression, optimal time lags were tested through the
regression of each media network?s agenda against its past agenda until
the latter no longer predicted its present agenda. Using STATA to run
OLS regression to estimate Granger causality, linear relationships were
then developed that regressed each of the five aggregated media network agendas based on both their past agenda and the agenda of the
other four media networks. For example, traditional media?s agendasetting influence on the right-leaning blog network would be estimated
using both traditional media?s past agenda and the right-leaning blog
network?s past agenda as predictors. Running these tests provided t-values of significance based on each medium?s intermedia agenda-setting
ability for other media networks.
Given that results of a time series analysis are more reliable with
more than 50 time points,42 all 56 usable time points through the
three issue periods were pooled to create greater opportunity to decipher media and blog influence on each other. At the individual issue
level, the only issue that yielded a lengthy enough time period to
avoid an overly inflated error term (and a failure to reject the null
hypothesis) was the Petraeus Report/MoveOn ?Betray Us? Ad issue,
which persisted for 40 days. This latter issue provided 38 usable lags for
measuring intermedia agenda-setting effects among the five media networks.
Results
182
Correlating Issue Agendas Across Media Entities. Before specific
hypotheses and research questions were examined, intraclass correlation coefficients (ICCs) were calculated, issue-by-issue, on the frequency
of postings and article content on each issue in an effort to provide a
measure of broad agreement among the five different media networks.
ICC is similar to Pearson?s correlation, but useful for non-independent
datasets like those in this study.
JOURNALISM & MASS COMMUNICATION QUARTERLY
TABLE 2
Blog-to-Blog and Blog-to-Media Correlations for the Petraeus Report
and the MoveOn ?Betray Us? Ad on the Iraq Issue
Right
Left
Moderate
TMediaA
TMediaB
Right
Left
.165
Moderate
.638*
.308*
TMediaA
.381*
.474*
.365*
TMediaB
.140
.308*
.565*
.272*
Note: Due to space constraints, within Table 2, Left refers to the agenda of left-leaning blogs, Right
refers to the agenda of right-leaning blogs, TMediaA refers to the agenda of traditional media?s
online news articles, and TMediaB refers to agenda of traditional media?s blog postings.
*p < .05
Table 1 provides a summary of issue mentions across the five
media networks. Of the three issues, the Petraeus Report/MoveOn issue
was the only issue that yielded a significant correlation (r = .415, p < .05)
across all five network agendas (left-leaning blogosphere, right-leaning
blogosphere, the moderate blogosphere, traditional media?s online
news, and traditional media blog). For the Craig issue, the ICC was
insignificant (r = .022, p > .05) for broad agreement across the five networks. Similarly, the ICC was insignificant for the Gonzales issue
(r = -.058, p > .05) across all five network agendas.
Pairwise correlations were then run between the networks to
determine whether any two networks yielded significant correlation
coefficients. As Table 2 highlights, only the Petraeus Report/MoveOn
issue yielded significant correlations across all network agendas.
Significant correlations on this issue ranged from .272 to .638, and all
blog networks showed correlations with the media agenda. Both the leftleaning and the moderate network also had strong correlations with the
media blog agenda; however, only the right-leaning blogosphere did not
have an agenda that correlated with the media blog agenda.
For the remaining two issues, few significant correlations were
derived; yet, a consistent finding was the moderate blogosphere?s strong
correlation with traditional media?s blog agenda (a relationship which
provides moderate support for H2). For the Craig issue, significant correlations were found between the moderate network and the left-leaning
blogosphere (r = .456, p < .05), as well as between the moderate blogosphere and the media blog agenda (r = .490, p < .05). For the Gonzales
issue, the only significant correlation was a correlation between the
moderate blogosphere and the media blog agenda (r = .572, p < .05). For
all three issues, both the moderate blogosphere and traditional media?s
blog agenda shared strong correlations.
ICC findings revealed uncorrelated issue agendas between the
left-leaning and right-leaning networks; however, to test H1 fully, it was
USING TIME SERIES ANALYSIS TO MEASURE INTERMEDIA AGENDA-SETTING INFLUENCE
183
TABLE 3
One-day Lag Significance Values for Media Network Setting Its Own Agenda
Right
Left
Moderate
TMediaA
TMediaB
Right
3.56*
.
.
Left
6.66*
.
Moderate
.
.
3.38*
.
TMediaA
.
6.39*
TMediaB
.
3.69*
Note: Due to space constraints, within Table 3, Left refers to the agenda of left-leaning blogs, Right
refers to the agenda of right-leaning blogs, TMediaA refers to the agenda of traditional media?s
online news articles, and TMediaB refers to agenda of traditional media?s blog postings.
* p < .05
184
important to correlate the issue agendas of blogs within their ideological social networks. Such analysis would answer the important question: Do left-leaning blogs and right-leaning blogs share a similar issue
agenda with other blogs within their ideological perspective?
H1 gained consistent support within the left-leaning blogosphere,
though the correlation coefficients could be described as weak. The ICC
for the agenda of the six left-leaning blogs on the Craig issue was significant (r = .292, p < .05). Regarding the Gonzales issue, the ICC was also
significant (r = .225, p < .05) among all six left-leaning blog agendas.
Finally, on the Petraeus Report/MoveOn issue, the ICC among the six
left-leaning blog agendas proved significant (r = .521, p < .05).
H1 gained only qualified support within the right-leaning blog
network, with the strongest support gained for the Petraeus Report/
MoveOn issue. The ICC was highest for this issue (r = .403, p < .05), but
barely significant for the Craig issue (r = .131, p = .05); however, the ICC
was insignificant for the Gonzales issue (r= -.064, p > .05).
Testing Intermedia Agenda in Traditional Media and Political
Blog Networks. These data reveal correlations among agendas among
the five different media outlets (left-leaning blogs, right-leaning blogs,
moderate blogs, traditional media, and traditional media blogs), but correlation coefficients are not evidence of causation. In an effort to determine directional influence, OLS regression was used to estimate Granger causality. These hypotheses also required a test of how effective the
media network was at setting its own agenda, which was best predicted
by a one-day lag interval (Table 3). Hypotheses were then tested by
combining all issues into a pooled issue. Additionally, tests were conducted at the individual issue level using the Petraeus Report/MoveOn issue.
Isolating the most well-known and likely source of traditional
media influence, H2 predicted that traditional media?s online news
agenda would be more likely to set the issue agenda of political blogs
than the reverse relationship. This hypothesis was only partially supported, at both the pooled issue level and at the individual issue level,
JOURNALISM & MASS COMMUNICATION QUARTERLY
TABLE 4
Pooled Issue Data Testing Traditional Media to Political Blog Agenda Setting
Granger Test
Left blog does not Granger cause
Right blog does not Granger cause
Moderate blog does not Granger cause
TMediaA does not Granger cause
TMediaB does not Granger cause
Media
Right blog
Moderate blog
TMediaA
TMediaB
Result
2.83*
1.19
2.62*
1.98
Left blog
Moderate blog
TMediaA
TMediaB
0.53
-0.20
3.18*
1.11
Left blog
Right blog
Moderate blog
TMediaB
1.29
2.28*
2.18*
3.06*
Left blog
Right blog
TMediaA
TMediaB
Left blog
Right blog
Moderate blog
TMediaA
1.97
2.32*
5.02*
2.85*
0.47
0.58
0.17
3.04*
Note: Due to space constraints, within Table 4, Left refers to the agenda of left-leaning blogs, Right
refers to the agenda of right-leaning blogs, TMediaA refers to the agenda of traditional media?s
online news articles, and TMediaB refers to agenda of traditional media?s blog postings. All reported results represent t-values between the two media agendas that test Granger causality.
* p < .05
because of traditional media?s inability to set the left-leaning blog agenda. Table 4 presents the results at the pooled issue level, while Table 5
presents these results at the individual issue level. Using the syntax of
Granger causality, noting that the words ?agenda setting? are substituted with the word ?cause,?43 traditional media online news sites did
Granger cause the right-leaning blog agenda through the pooled issue
level (t[2, 54] = 2.28, p < .05) and the individual issue level (t[2, 36] = 3.15,
p < .05), the moderate blog agenda through the pooled issue level (t[2, 54]
= 2.18, p < .05) and the individual issue level (t[2, 36] = 2.05, p < .05) , and
its own media blog agenda through the pooled issue level (t[2, 54] = 3.06,
p < .05), and the individual issue level (t[2, 36] = 3.64, p < .05). But, traditional media online news sites did not Granger cause the left-leaning
blog agenda at either the pooled issue level (t[2, 54] = 1.29, p > .05) or the
individual issue level (t[2, 36] = -1.18, p > .05).
H3 predicted that political blogs would not be successful at setting
one another?s agenda; however, this was also unsupported. Through the
USING TIME SERIES ANALYSIS TO MEASURE INTERMEDIA AGENDA-SETTING INFLUENCE
185
TABLE 5
Individual Issue Data Testing Traditional Media to Political Blog Agenda Setting
Granger Test
Left blog does not Granger cause
Right blog does not Granger cause
Moderate blog does not Granger cause
TMediaA does not Granger cause
TMediaB does not Granger cause
Media
Right blog
Moderate blog
TMediaA
TMediaB
Left blog
Moderate blog
TMediaA
TMediaB
Left blog
Right blog
TMediaA
TMediaB
Left blog
Right blog
Moderate blog
TMediaB
Left blog
Right blog
Moderate blog
TMediaA
Result
4.12*
2.13*
3.75*
3.36*
0.10
0.36
2.38*
1.34
0.74
2.24*
4.22*
2.24*
0.83
3.15*
2.05*
3.64*
-1.18
0.22
-0.05
1.76
Note: Due to space constraints, within Table 5, Left refers to the agenda of left-leaning blogs, Right
refers to the agenda of right-leaning blogs, TMediaA refers to the agenda of traditional media?s
online news articles, and TMediaB refers to agenda of traditional media?s blog postings. All reported results represent t-values between the two media agendas that test for Granger causality.
*p < .05
186
pooled issue level and the individual issue level, political blogs did
Granger set each other?s agenda. As Tables 4 and 5 show, the left-leaning blog network did Granger cause the agenda of the right-leaning blogosphere network at the pooled issue level (t[2, 54] = 2.83, p < .05) and
the individual issue level (t[2, 36] = 4.12, p < .05). Right-leaning blogs
had less agenda-setting power on other blogs, and in both scenarios
(pooled and individual issue level), this network was unable to set the
agenda of other political blogs. An interesting scenario of the moderate
blog?s power is shown by its agenda-setting ability: the moderate blog
network did Granger cause the issue agenda of the right-leaning blogosphere at the pooled issue level (t[2, 54] = 2.32, p < .05) and the individual issue level (t[2, 36] = 2.24, p < .05). However, the moderate blog network did not Granger cause the left-leaning blog network?s agenda at
both the pooled issue level and the individual issue level.
Were the political blog networks able to set traditional media?s
online news issue agenda (blog and traditional news websites)? In
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answer to RQ1 and RQ2, Tables 4 and 5 also provide solid evidence that
all blog networks had success at setting traditional media?s online news
agenda (as opposed to traditional media?s blog agenda) at the pooled
issue level and the individual issue level. The left-leaning blogosphere
was successful at setting traditional media?s agenda through the pooled
issue level (t[2, 54] = 2.62, p < .05) and the individual issue level (t[2, 36]
= 3.75, p < .05). Similarly, the right-leaning blogosphere wielded influence over traditional media?s agenda through the pooled issue level (t[2,
54] = 3.18, p < .05) and the individual issue level (t[2, 36] = 2.38, p < .05).
Unlike the left-leaning or the right-leaning blogosphere, the moderate
blogosphere influenced the issue agendas of traditional media?s online
news site through both the pooled issue level (t[2, 54] = 5.02, p < .05) and
the individual issue level (t[2, 36] = 4.22, p < .05), as well as traditional
media?s blog agenda through both the pooled issue level (t[2, 36] = 2.85,
p < .05) and the individual issue level (t[2, 36] = 2.24, p < .05).
RQ3 probed the effectiveness of the tradition