Does Offline Political Segregation Affect the Filter Bubble? An Empirical Analysis of Information Diversity for Dutch and Turkish Twitter Users E. Bozdaga,∗, Q. Gaob, G.J. Houbenc, M.E. Warnierd aDelft University of Technology, Department Values and Technology, P.O. Box 5015 2600 GA Delft, The Netherlands bPhilips Research, Eindhoven, the Netherlands cDelft University of Technology, Web Information Systems Group, Delft, the Netherlands d Delft University of Technology, Section of System Engineering. Delft, the Netherlands Abstract From a liberal perspective, pluralism and viewpoint diversity are seen as a necessary condition for a well-functioning democracy. Recently, there have been claims that viewpoint diversity is diminishing in online social networks, putting users in a \bubble", where they receive political information which they agree with. The contributions from our in- vestigations are fivefold: (1) we introduce different dimensions of the highly complex value viewpoint diversity using political theory; (2) we provide an overview of the metrics used in the literature of viewpoint diversity analysis; (3) we operationalize new metrics using the theory and provide a framework to analyze viewpoint diversity in Twitter for different political cultures; (4) we share our results for a case study on minorities we performed for Turkish and Dutch Twitter users; (5) we show that minority users cannot reach a large percentage of Turkish Twitter users. With the last of these contributions, using theory from communication scholars and philosophers, we show how minority access is missing from the typical dimensions of viewpoint diversity studied by computer scientists and the impact it has on viewpoint diversity analysis. Keywords: Twitter, diversity, polarization, politics, Turkey, Netherlands 1. Introduction Dryzek, 1994). Exposure to biased news information can foster intolerance to opposing viewpoints, lead to ideolog- It is well known that traditional media have a bias in ical segregation and antagonisms in major political and selecting what to report and in choosing a perspective on a social issues (Glynn et al., 2004; An et al., 2012; Saez- particular topic. Individual factors such as personal judg- Trumper et al., 2013). Being aware of and overcoming ment can play a role during the selection of news for a bias in news reporting is essential for a fair society, as me- newspaper. Selection bias, organizational factors, adver- dia has the power to shape voting behavior (Saez-Trumper tiser and government influences can all affect which items et al., 2013). will become news (Bozdag, 2013). About 37% of Ameri- Social information streams, i.e., status updates from cans see a great deal of political bias in news coverage and social networking sites, have emerged as a popular means 68% percent prefer to get political news from sources that of information sharing. Political discussions on these plat- have no particular point of view (Pew Research, 2012). forms are becoming an increasingly relevant source of po- Similarly, in a survey performed before the general elec- litical information, often also used as a source of quotes tions in the UK, 96% of the population said they believe for media outlets (J¨urgenset al., 2011). Traditional me- arXiv:1406.7438v1 [cs.SI] 28 Jun 2014 they have seen clear bias within the UK media (Wei et al., dia are declining in their gatekeeping role to determine the 2013). Evidence of bias ranges from the topic choice of agenda and select which issues and viewpoints reach their the New York Times to the choice of think-tanks that the audiences (Bruns, 2011). Internet users have moved from media refer to (DellaVigna & Kaplan, 2007). scanning traditional media such as newspapers and televi- Many democracy theorists claim that modern delibera- sion to using the Internet, in particular social networking tive democracy requires citizens to have socially validated sites (An et al., 2012). Social networking sites are thus and justifiable preferences. Citizens must be exposed to now acting as gatekeepers (Bozdag, 2013). opposed preferences and viewpoints and should be able Communication theorists argue that the traditional me- to defend their views (Held, 2006; Offe & Preuss, 1990; dia are declining in their gatekeeping role to determine what is \newsworthy" and select which issues and view- ∗Corresponding author points will reach their audiences Bruns (2011). It is often Email addresses: [email protected] (E. Bozdag), argued that the Internet, by promoting equal access to [email protected] (Q. Gao), [email protected] (G.J. diverging preferences and opinions in society, actually in- Houben), [email protected] (M.E. Warnier) Preprint submitted to Computers in Human Behavior (forthcoming) August 16, 2018 creases information diversity. Many scholars characterize diversity. the online media landscape as the \age of plenty, with In this paper, we contribute with a framework to an- an almost infinite choice and unparalleled pluralization of alyze and understand the impact of political culture in voices that have access to the public sphere (Karppinen, Twitter. Rather than reducing the concept viewpoint di- 2009). Some argue that social media will disrupt the tra- versity to a single quantity or metric, we introduce differ- ditional elite control of media and amplify the political ent dimensions of viewpoint diversity, based on previous voice of non-elites and minorities (Castells, 2011).Still oth- studies and the theory from communication studies and ers claim that tools such as Twitter are neutral spaces for political philosophy. In addition, we provide a set of new collaborative news coverage operated by third parties out- metrics and operationalize them. Finally, we present the side the journalism industry. As a result, the information result of a case study we performed for Dutch and Turkish curated through collaborative action on such social media Twitter users using this framework. We show that minor- platforms should be expected to be drawn from a diverse, ity users cannot reach a large percentage of the studied multi-perspectival range of sources (Bruns, 2011). Some Turkish Twitter users and political culture is making a further claim that platforms such as Twitter are neutral difference. communication spaces, and offer a unique environment in which journalists are free to communicate virtually any- 2. Empirical Studies of Information Diversity in thing to anyone, beyond many of the natural constraints Social Media posed by organizational norms that are existing in tradi- tional media (Lasorsa et al., 2012). An empirical study performed by Facebook suggests On the other hand, there are skeptical voices that argue that online social networks may increase the spread of that the Internet has not fundamentally changed the con- novel information and of diverse viewpoints. According centrated structure typical of mass media, but reflects the to Bakshy (2012), even though people are more likely to previously recognized inequalities (Karppinen, 2009). It is consume and share information that comes from close con- also argued that it has brought about new forms of exclu- tacts that they interact with frequently, the vast major- sion and hierarchy (Suoranta & Vad´en,2009). While it has ity of information comes from contacts that they interact increased some sort of political participation, it has em- with infrequently. These so-called \weak-ties" (Granovet- powered a small set of elites and they still strongly shape ter, 1981) are also more likely to share novel information. how political material is presented and accessed (Hindman, However, there are some concerns with this study. First, 2008). Others have pointed out the danger of \cyberbalka- Facebook does not provide open access to everyone, thus nization"" caused by the Internet(Sunstein, 2002; Pariser, we can not repeat or reproduce the results using Facebook 2011). They argue that the filters we choose on the Inter- data. Second, our weak ties give us access to new stories net, or the filters that are imposed upon us will weaken the that we would not otherwise have seen, but these stories democratic process. This is because it will allow citizens to might not be different ideologically from our own general join into groups that share their own views and values, and worldview. They might be novel information, but not par- cut themselves off from any information that might chal- ticularly diverse. The concepts serendipity, diversity and lenge their beliefs. Group deliberation among like-minded novelty are different from each other (Sun et al., 2013). people can create polarization; individuals may lead each The Facebook research does not indicate whether we en- other in the direction of error and falsehood, simply be- counter and engage with news that opposes our own beliefs cause of the limited argument pool and the operation of through \weak-links". social influences. Twitter, with its API, provides an excellent environ- It is thus very important to verify whether viewpoint ment for information diversity research. An et al. (2012) diversity is diminishing in social media and whether cyber- observe extreme polarization among media sources in Twit- balkanization indeed occurs. There are empirical studies ter. In another study, they found that, when direct sub- that have observed a high level of information diversity in scription is considered alone, most Twitter users receive Twitter and Facebook, mainly due to retweets and weak- only biased political views they agree with (An et al., ties (Bakshy et al., 2012; An et al., 2011; Sun et al., 2013). 2011). However, they note that the news media land- While being very valuable contributions to the literature, scape changes dramatically under the influence of retweets, these studies often focus on American users and they de- broadening the opportunity for users to receive updates fine information diversity either as \novelty", or \source from politically diverse media outlets. Sun et al. (2013) diversity". However, as we will show below, novel infor- performed an empirical study using statistical models to mation does not necessarily contribute to information di- identify serendipity in Twitter and Weibo.