As people increasingly turn to social networks for news and civic

information, questions have been raised about whether this practice

leads to the creation of echo chambers, in which people are exposed

only to information from like-minded individuals [2]. Other speculation

has focused on whether algorithms used to rank search results and

social media posts could create filter bubbles, in which only

ideologically appealing content is surfaced [3].

Research we have conducted to date, however, runs counter to this

picture. A previous 2012 research paper concluded that much of the

information we are exposed to and share comes from weak ties:

those friends we interact with less often and are more likely to be

dissimilar to us than our close friends [4]. Separate research suggests

that individuals are more likely to engage with content contrary

to their own views when it is presented along with social information

[5].

Our latest research, released today in Science, quantifies, for the first

time, exactly how much individuals could be and are exposed to

ideologically diverse news and information in social media [1].

We found that people have friends who claim an opposing political

ideology, and that the content in peoples' News Feeds reflect those

BLOG POST

Exposure to Diverse Informationon Facebookby 8 Eytan Bakshy, Solomon Messing, Lada Adamic

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Research Search publications, events and more

diverse views. While News Feed surfaces content that is slightly more

aligned with an individual's own ideology (based on that person's

actions on Facebook), who they friend and what content they click on

are more consequential than the News Feed ranking in terms of how

much diverse content they encounter.

Specifically, we find that among those who self-report a liberal or

conservative affiliation,

On average, 23 percent of people's friends claim an opposing

political ideology.

Of the hard news content that people's friends share, 29.5

percent of it cuts across ideological lines.

When it comes to what people see in the News Feed, 28.5

percent of the hard news encountered cuts across ideological

lines, on average.

24.9 percent of the hard news content that people actually

clicked on was cross-cutting.

Sharing news on Facebook

During the six months between July 2014 and January 2015, more

than 7 million distinct Web links (URLs) were shared by people on

Facebook in the United States. We were interested in learning how

much people were exposed to hard news stories about politics,

world affairs, and the economy, rather than soft news stories

about entertainment, celebrities, and sports and whether this

information was aligned primarily with liberal or conservative

audiences. To do this, we trained a support vector machine classifier

which uses the first few words of articles linked for each URL shared

on Facebook. This allowed us to identify more than 226,000 unique

hard news articles that had been shared at least 100 times.

Next, we characterized the content as either conservative or liberal.

Nine percent of Facebook users in the United States self-report their

political affiliation on their profiles. We mapped the most common

affiliations to a five-point scale ranging from -2 (very liberal) to 2 (very

conservative). By averaging the affiliations of those who shared each

article, we could measure the ideological alignment of each story. To

be clear, this score is a measure of the *ideological alignment of the

audience* *who shares an article*, and is not a measure of political

bias or slant of the article. This calculation is described in the

illustration below.

Illustration of how ideological alignment for content is measured. For

each shared item, we average the political affiliation of individuals

who share. For example, in the left most example above, the article

was shared by five people, three whom identified themselves as

liberals, one as a moderate, and one as conservative, producing an

average of -2/5.

When we average this measure for every story from a particular

website domain, we can see key differences in well-known

ideologically-aligned media sources: FoxNews.com is aligned with

conservatives (As = +.80), while HuffingtonPost.com is aligned with

liberals (As = -.65). There was substantial polarization among hard

news shared on Facebook, with the most frequently shared links

clearly aligned with largely liberal or conservative populations, as

shown below.

This figure shows that most links to particular hard news articles are

shared either primarily by liberals (alignment score close to -1) or by

conservatives (alignment score close to +1) but rarely by both

equally.

Using the methods described above, we turned toward measuring the

extent to which people could be, and are exposed to ideologically

diverse information on Facebook.

Network structure and ideology

Homophily, the tendency for similar individuals to associate with each

other (birds of a feather flock together,) is a robust social

phenomenon. Friends are more likely to be similar in age, educational

attainment, occupation, and geography. It is not surprising to find that

the same holds true for political affiliation on Facebook. We can see

how liberals and conservatives tend to connect to people with similar

political affiliations based on sample ego-networks depicted in the

visualizations below.

Example social networks for a liberal, a moderate, and a

conservative. Points are individuals' friends, and lines designate

friendships between them.*

However, among those who report their ideology, on average, about

23 percent of their friends report an affiliation on the opposite side of

the ideological spectrum. From the figure below, we can see that there

is a wide range of network diversity. Half of users have between

between 9 and 33 percent of friends from opposing ideologies, while

25 percent have less than 9 percent and the remaining 25 percent

have more than 33 percent.

Percent of friends from opposing ideologies among liberals and

conservatives.

The flow of information on Facebook

The diversity of content people encounter depends not only on who

their friends are, but also what information those friends share, and

the interaction between people and Facebook's News Feed. News

Feed shows you all of the content shared by your friends, but the most

relevant content is shown first. Exactly what stories people click on

depends on how often they use Facebook, how far down they scroll in

the News Feed, and the choices they make about what to read.

Illustration of how the exposure process consists of three phases: (1)

the news your friends share (Potential from network), (2) ranking and

the time that individuals take to scroll governs what they see in their

News Feeds (Exposed), (3) clicking through to actual article

(Selected).

How much cross-cutting content people encounter depends on who

their friends are and what information those friends share. If people

were to acquire information from random others, approximately 45

percent of the content liberals would be exposed to would be cross

cutting, compared to 40 percent for conservatives. Of course,

individuals do not encounter information at random in offline

environments nor on the Internet.

How much of the cross-cutting content shared by your friends appears

in News Feed? People are eligible to see all of the content shared by

their friends in News Feed, but since people don't have enough time in

the day to see everything, we sort the content to show people what is

most relevant to them. We found that 23 percent of news shared by

liberals friends is cross-cutting, whereas what is seen in the News

Feed is 22 percent. This corresponds to a risk ratio of 8 percent,

meaning that people were 8 percent less likely to see countervailing

articles that have been shared by friends, compared to the likelihood

of seeing ideologically consistent articles that have been shared by

friends. On the other hand, 34 percent of the content shared by

conservatives is ideologically cross-cutting, versus 33 percent actually

seen in the News Feed, corresponding to a risk ratio of 5 percent.

How much cross-cutting content that appears in News Feed do people

actually click on? While 22 percent of the content seen by liberals was

cross-cutting, we found that 20 percent of the content they actually

clicked on was cross-cutting (meaning people are 6 percent less likely

to click on countervailing articles that appeared in their News Feed,

compared to the likelihood of seeing ideologically consistent articles

that appeared in their News Feed). Conservatives saw 33 percent of

cross-cutting content in News Feed but actually clicked on 29 percent

(corresponding to a risk ratio of 17 percent).

The diversity of content (1) shared by random others (random), (2)

shared by friends (potential from network), (3) actually appearing in

peoples News Feeds (exposed), (4) clicked on (selected).

When we look at people on the margin of encountering hard news

on Facebook, we see more evidence of the important role individual

choice plays. Take people whose friends shared at least one

consistent and one cross-cutting story --- 99 percent of them were

exposed to at least one ideologically aligned item, and 96 percent

encountered at least one ideologically cross-cutting item in News

Feed. When we looked at who clicked through to hard news content,

we found that 54 percent---more than half---clicked on ideologically

cross-cutting content, although less than the 87 percent who clicked

on ideologically aligned content.

Proportion of individuals with at least one cross-cutting and aligned

story (1) shared by friends (potential), (2) actually appearing in

peoples News Feeds (exposed) (3) clicked on (selected).*

Discussion

By showing that people are exposed to a substantial amount of

content from friends with opposing viewpoints, our findings contrast

concerns that people might list and speak only to the like-minded

while online [2]. The composition of our social networks is the most

important factor affecting the mix of content encountered on social

media with individual choice also playing a large role. News Feed

ranking has a smaller impact on the diversity of information we see

from the other side.

We believe that this work is just the beginning of a long line of

research into how people are exposed to and consume media online.

For more information, see our paper, which is available on open

access at ScienceExpress:

Exposure to Ideologically Diverse News and Opinion. E. Bakshy, S.