What did you see? Personalization, regionalization and the question of the filter bubble in Google's search engine

Abstract: This report analyzes the Google search results from more than 1,500 volunteer data donors who, in the five weeks leading up to the federal election on September 24th, 2017, automatically searched Google for 16 predefined names of political parties and politicians every four hours. It is based on an adjusted database consisting of more than 8,000,000 data records, which were generated in the context of the research project "#Datenspende: Google und die Bundestagswahl 2017" and sent to us for evaluation. The #Datenspende project was commissioned by six state media authorities. Spiegel Online acted as a media partner. Focal points of the present study are, i.a., the question of the degree of personalization of search results, the proportion of regionalization and the risk of algorithm-based filter bubble formation or reinforcement by the leader in the search engine market.