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Digital Societies: The influence of web search engines on political opinion formation (ESUPOL)


Web search engines have become an important source when people seek information. While search engine queries play an essential role in obtaining political information, to this date, only little is known about potential challenges and consequences that may emerge from this behavior. The project was funded by the Ministry of Culture and Science of the German State of North Rhine-Westphalia and aimed to provide insight into the influence of web search engines on political opinion formation. Researchers from the Cologne Center for Comparative Politics and TH Köln (University of Applied Sciences) were part of the interdisciplinary team. In this project, we collected large amounts of web data from various search engines and analyzed them with methods and techniques of natural language processing. Subsequent experiments provided insights into the causal relations between search engines and political opinion formation. The studies provided fundamental insights into securing and strengthening democracy in a digital society in which search engines play a major role in political information gathering.

One study (link) systematically analyzed information for German political actors to see if there are such biases in search engines. A subsequent online experiment in Germany focused on investigating the potential effects of biased information in the context of a salient political topic, i.e., refugees. Another comparative study went beyond Germany and analyzed latent interest in European politicians in online search in multiple European countries, which has not yet been possible with other publicly available search query data. Important findings were that information displayed in Google search suggestions for politicians and their Wikipedia articles, which most users visit after Google searches, can be biased by their party and gender identity. However, other social identities seem to be more crucial for the latent interest in political actors in the European political online search, especially the nationality of political actors as well as having a supranational political role. Moreover, the project uncovered that a strong political group identity plays a crucial role in how politically biased information influences political attitudes and how individuals engage with it online. Particularly, the experiment showed that negatively biased political information about refugees in search engines has a polarizing effect on asylum attitudes among individuals at the left and right margins of the political spectrum who also show a confirmation bias in intended click behavior. The project findings imply that media literacy in education and more research are needed to identify and address new challenges to democracy due to the increasing importance of online search.

The project is part of the state-wide graduate institute on digital societies (link).


Cologne Center for Comparative Politics:

Principal investigator: Prof. Sven-Oliver Proksch (Professor for European and Multilevel Politics)

Doctoral researcher: Franziska Pradel

TH Köln

Principal investigator: Prof. Philipp Schaer (Professor for Information Retrieval) 

Doctoral researchers: Fabian Haak, Malte Bonart


Pradel, Franziska (2021). Biased representation of politicians in Google and Wikipedia search? The joint effect of party identity, gender identity and elections. Political Communication, 38(4), 447-478. (Link)


Working Papers:

Pradel, Franziska, Haak, Fabian, Proksch, Sven-Oliver, Schaer, Philipp. Googling European politicians: A comparative analysis of autocomplete predictions.


Pradel, Franziska. The Impact of Hate Speech in Search Engines on Political Attitudes – Evidence from an Online Experiment.


Funded by:

Ministerium für Kultur und Wissenschaft (MKW) des Landes Nordrhein-Westfalen

04.10.2017 - 31.12.2022