Academic Committees
| since 2008 | Member of the executive committee of the Special Interest Group Information Retrieval within the German Informatics Society (2008-2017 as deputy speaker) |
| since 2020 | Member of the executive committee of the Working Group „Data Engineering for Data Science“ within the German Informatics Society |
| since 2019 | Member of the executive committee of the Working Group „Foundations of Information Systems“ within the German Informatics Society |
| since 2015 | Member of the advisory board of the Fachinformationsdienstes Pharmazie, TU Braunschweig |
| since 2019 | Member of the advisory board of the dblp Computer Science Bibliography |
Editor of collections
- Andreas Harth, Katja Hose, Ralf Schenkel (Hrsg.): Linked Data Management. Chapman and Hall/CRC 2014, ISBN 978-1-4665-8240-8
- Henk M. Blanken, Torsten Grabs, Hans-Jörg Schek, Ralf Schenkel, Gerhard Weikum (Hrsg.): Intelligent Search on XML Data, Applications, Languages, Models, Implementations, and Benchmarks. Lecture Notes in Computer Science 2818, Springer 2003, ISBN 3-540-40768-5
Editorial Boards of Journals
- Editor in Chief of the Datenbank-Spektrum (SpringerNature) (since 2011)
- Editor of the issue on "Data Engineering for Data Science" (with Stefanie Scherzinger and Marina Tropmann-Frick), November 2021
- Editor of the issue on "Big Data Analytics and Exploration" (with Sebastian Michel and Rainer Gemulla), July 2018
- Editor of the issue on "Information Retrieval" (with Christa Womser-Hacker), March 2014
- Editor of the issue on "Social Mining and Search" (with Benno Stein), June 2010
- Member of the Editorial Board of Information Systems (Elsevier)
Organisation of Events
- Autumn School "Information Retrieval and Foraging" (ASIRF), August 2025 (with Thomas Mandl, U Hildesheim, and Philipp Schaer, TH Köln)
- Autumn School "Information Retrieval and Foraging" (ASIRF), September 2023 (with Norbert Fuhr, U Duisburg-Essen, and Philipp Schaer, TH Köln)
- Workshop "Data Engineering for Data Science", BTW 2023 (with Ansgar Scherp, U Ulm)
- Workshop "Data Engineering for Data Science" of the Special Interest Group Database Systems at the LWDA 2021 (with Stefanie Scherzinger, U Passau, and Marina Tropmann-Frick, UAW Hamburg)
- Autumn School "Information Retrieval and Foraging" (ASIRF), September 2019 (with Norbert Fuhr, U Duisburg-Essen, and Ingo Frommholz)
- Workshop "Grundlagen von Datenbanken", March 2019
- Autumn School "Information Retrieval and Foraging" (ASIRF), September 2018 (with Norbert Fuhr, U Duisburg-Essen, and Ingo Frommholz)
- 5th International Workshop “Data Engineering meets Semantic Web”, ICDE 2014 (with K. Hose, U Aalborg, J. Umbrich, DERI Irland, C. Gutierrez, U Chile)
- 1st Joint International Workshop „Entity-oriented and Semantic Search“, SIGIR 2012 (with K. Balog, D. Carmel, A. de Vries, D. M. Herzig, P. Mika, H. Roitman, P. Serdyukov, T. Tran Duc)
- Workshop der GI-Fachgruppen Datenbanken und Information Retrieval, March 2012 (with Wolf-Tilo Balke, TU Braunschweig)
- 10th International Workshop of the Initiative for the Evaluation of XML Retrieval (as local organizer), December 2011
- Workshop „Searching and Mining Entity-Relationship Data“, CIKM 2011 (with Haggai Roitman, IBM Haifa, and Marko Grobelnik, IJS Ljubljana)
- Workshop “Exploiting Semantic Annotations for Information Retrieval”, CIKM 2010 (with Jaap Kamps, U Amsterdam, and Jussi Karlgren, SICS Stockholm)
- Autumn School 2010 of the GI Special Interest Group Information Retrieval
- Co-Chair of the „Initiative for the Evaluation of XML Retrieval” (INEX) 2010-2014, Co-chair of the Efficiency Track (2008-2009, with Martin Theobald, MPI-INF) and the Linked-Data-Track (2013, with Martin Theobald, University of Antwerp, and Quiyue Wang, Renmin University of China)
- Workshop „WebDB meets IR“ of the working group „WebDB“ und der GI Special Interest Group „Information Retrieval“, BTW 2005 (with Wolfgang Müller, Universität Bamberg)
Program Committees
- PC Co-Chair, 21st Conference on Database Systems for Business, Technology and Web (BTW 2025), Bamberg
- Senior PC Member
- ACM SIGIR Int. Conference on Research & Development on IR: 2023-2026
- European Conference on Information Retrieval (ECIR): 2023-2026
- Int. Conference on Information and Knowledge Management (CIKM): 2022-2025 (Research Track), 2024-2025 (Demo)
- ACM Int. Conference on Web Search and Data Mining (WSDM): 2026 (Short Papers)
- ACM Web Conference: 2026 (Short Papers)
- PC Member (incomplete)
- ACM SIGIR Int. Conference on Research & Development on IR: 2007-2008 (Research), 2010-2022 (Research), 2023-2024 (Demo)
- European Conference on Information Retrieval (ECIR): 2006-2016, 2021
- International Conference on the Theory of Information Retrieval (ICTIR): 2020-2024
- Int. World Wide Web Conference (WWW): 2010, 2012, 2013, 2017 (short), 2018
- ACM Conference on Web Search and Data Mining (WSDM): 2010, 2011, 2021, 2022
- Int. Conference on Information and Knowledge Management (CIKM): 2005, 2011-2018, 2020, 2021
- Int. Conference on Very Large Databases (VLDB): 2006, 2007 (Demo), 2008, 2010, 2017 (Demo), 2018, 2021, 2027
- ACM SIGMOD Int. Conference on Management of Data: 2009 (Demo), 2010, 2021 (Demo), 2027
- IEEE Int. Conference on Data Engineering (ICDE): 2009, 2010, 2012, 2014, 2015, 2019, 2026 (demo)
- Int. Conference on Extending Database Technology (EDBT): 2008, 2012 (demo), 2014, 2022, 2024, 2026
- ACM SIGKDD Conference on Knowledge Discovery and Data Mining: 2010, 2013-2016, 2018
- International Semantic Web Conference (ISWC): 2019-2025
- Extended Semantic Web Conference (ESWC): 2017-2019 (Posters&Demos), 2023-2026
- Conference on Database Systems for Business, Technology and Web (BTW): 2005, 2007, 2023
- Joint Conference on Digital Libraries (JCDL): 2018, 2019, 2022-2025
Tutorials and invited talks
- Conversational Search (Tutorial, Autumn School for Information Retrieval and Foraging, 2025)
- Quality-Aware Argument Retrieval (Invited talk, Max-Planck-Institut für Informatik, Saarbrücken, 2023)
- Argument Mining and Retrieval (Tutorial, Autumn School for Information Retrieval and Foraging, 2023)
- Integrating and Exploiting Public Metadata Sources in a Bibliographic Information System (Keynote, Workshop Bibliographic Information Retrieval, 2018)
- Harvesting, Integrating, and Cleaning Metadata in a bibliographic Information System (Keynote, Workshop Grundlagen von Datenbanken, 2018)
- Information Retrieval Systems (Tutorial, Autumn School for Information Retrieval and Foraging, 2018 und 2019)
- Semistructured Data Search Evaluation (Tutorial, PROMISE Winter School 2013)
- Effizienzaspekte von Information Retrieval (Tutorial, GI-Herbstschule Information Retrieval 2008, 2012, 2014 und 2017)
- Database Techniques for Linked Data Management (Tutorial, SIGMOD 2012, with Andreas Harth and Katja Hose)
- Database Foundations for Scalable RDF Processing (Tutorial, Reasoning Web Summer School 2011, with Katja Hose and Martin Theobald)
- Semantic Knowledge Bases from Web Sources (Tutorial, CIKM 2010+IJCAI 2011, withHady Lauw, Fabian Suchanek, Martin Theobald, Gerhard Weikum)
- Wissensbasierte Suche (Tutorial, GI-Herbstschule Information Retrieval 2010 and 2017)
Reviewing
- Reviewer for the German Research Foundation (DFG), the Dutch Research Council (NWO), the Luxembourg National Research Fund (FNR) and the DAAD
- Reviewer of a habilitation at Trier University
- Reviewer of dissertations at TU Braunschweig, Universität Passau, Universität Ulm, Universität München, IIT Delhi, Universität des Saarlandes, Queen-Mary-University London, University of Tampere, Universität Freiburg, RPTU Kaiserslautern and Universität Trier
- Reviewer in appointment procedures at several universities
- Reviewer for Virtuelle Hochschule Bayern
- Reviewer for ACM Trans. on Database Systems (TODS), ACM Trans. on Information Systems (TOIS), ACM Trans. on the Web (TWEB), Information Retrieval (IR), IEEE Trans. on Knowledge and Data Engineering (TKDE), Information Processing Letters (IPL), Distributed and Parallel Databases (DAPD), ACM Computing Surveys, Information Systems