Web search engines are used by the majority of the people on a daily basis to inform themselves about news, people, political events and many other things. Therefore, search engines cannot only be reduced to the technical aspects and implementational details of the underlying IR systems. They are embedded in the society and a surrounding political and economical context.

As with the traditional media, problems of biases (e.g. towards a political ideology and sexism or racism), manipulation (e.g. spamming and SEO), missing diversity and fairness can arise. Moreover, due to the commercial interests of the search engines, the applied retrieval techniques are not transparently published and the collected data is not shared for research purposes.

The lack of transparency makes it hard for researchers to study and judge the impact of these ‘black boxes’. In addition, the lack of transparency makes it also difficult for the individual user to assess the quality of the retrieved content. Therefore, political debates around the regulation of search engines (and social media) arise in many countries.

The goal of this literature review is to gather and summarize relevant work in the areas of transparency and regulation of web search engines. It may be necessary to set the main focus to a special aspect (e.g. legal aspects of regulation, transparency in user interfaces, algorithmic audit, query auto-completions).

• Gasser, Urs & Thurman, James: Themen und Herausforderungen der Regulierung von Suchmaschinen. In Machill, Marcel & Beiler, Markus (ed.): Die Macht der Suchmaschinen = The power of search engines. Köln : Halem, 2007, S. 44-64.
• Google. 2018. Legal Removal Requests. https://support.google.com/legal/answer/3110420.
• Laura A. Granka. 2010. The Politics of Search: A Decade Retrospective. The Information Society 26, 5 (September 2010), 364–374. DOI:https://doi.org/10.1080/01972243.2010.511560
• Stavroula Karapapa and Maurizio Borghi. 2015. Search engine liability for autocomplete suggestions: personality, privacy and the power of the algorithm. International Journal of Law and Information Technology 23, 3 (September 2015), 261–289. DOI:https://doi.org/10.1093/ijlit/eav009
• Ke Yang, Julia Stoyanovich, Abolfazl Asudeh, Bill Howe, HV Jagadish, and Gerome Miklau. 2018. A Nutritional Label for Rankings. In Proceedings of the 2018 International Conference on Management of Data (SIGMOD ‘18). ACM, New York, NY, USA, 1773-1776. DOI: https://doi.org/10.1145/3183713.3193568