Event organization

• The 35th International Joint Conference on Artificial Intelligence (IJCAI-ECAI'26) (demonstrations track co-chair)
• The 18th European Conference on Symbolic and Quantitative Approaches to Reasoning with Uncertainty (ECSQARU'25) (co-chair)
• The First International Workshop on Trends in Knowledge Representation and Reasoning (TKR'25) (co-chair)
• The 10th International Conference on Computational Models of Argument (COMMA'24) (local chair)
• The 21st International Workshop on Non-Monotonic Reasoning (NMR'23) (co-chair)
• The 8th Workshop on Formal and Cognitive Reasoning (FCR'22) (co-chair)
• Workshop on Cognitive Aspects of Knowledge Representation (CAKR'22) (co-chair)
• The Fourth International Workshop on Systems and Algorithms for Formal Argumentation (SAFA'22) (co-chair)
• The First International Conference on Foundations, Applications, and Theory of Inductive Logic (FATIL'22) (general chair)
• The 19th International Conference on Principles of Knowledge Representation and Reasoning (KR'22), Applications and Systems Track (co-chair)
• The Third Workshop on Argument Strength (ArgStrength'21) (co-chair)
• The 7th Workshop on Formal and Cognitive Reasoning (FCR'21) (co-chair)
• The Third International Workshop on Systems and Algorithms for Formal Argumentation (SAFA'20) (co-chair)
• The 43rd German Conference on Artificial Intelligence (KI'20) (workshop and tutorial chair)
• The 8th Workshop on Dynamics of Knowledge and Belief (DKB'19) and the 7th Workshop KI and Kognition (KIK'19) (co-chair)
• The 7th Workshop on Dynamics of Knowledge and Belief (DKB'18) and the 6th Workshop KI and Kognition (KIK'18) (co-chair)
• The Second International Workshop on Systems and Algorithms for Formal Argumentation (SAFA'18) (co-chair)
• The 40th German Conference on Artificial Intelligence (KI'17) (program co-chair)
• The Second Summer School on Argumentation: Computational and Linguistic Perspectives (SSA'16) (co-chair)
• The First International Workshop on Systems and Algorithms for Formal Argumentation (SAFA'16) (co-chair)
• The First International Competition on Computational Models of Argumentation (ICCMA'15) (co-chair)
• The 28th International FLAIRS Conference - Uncertain Reasoning Track (FLAIRS'15) (co-chair)
• The 27th International FLAIRS Conference - Uncertain Reasoning Track (FLAIRS'14) (co-chair)
• The 43rd Annual German Conference on Informatics (Informatik'13) (local organization committee)
• The 36th German Conference on Artificial Intelligence (KI'13) (local chair)
• The Eleventh German Conference on Multiagent System Technologies (MATES'13) (co-chair)
• "AI on the Web", Workshop at the 35th Annual German Conference on Artificial Intelligence (AIW'12) (co-chair)
• The 28th International Symposium On Theoretical Aspects Of Computer Science (STACS'11) (local organization committee)

Program committee membership

• The 41st AAAI Conference on Artificial Intelligence (AAAI'27), Senior Program Committee member
• The 11th International Conference on Computational Models of Argument (COMMA'26)
• The 18th International Conference on Logic Programming and Nonmonotonic Reasoning (LPNMR'26)
• The 18th International Conference on Logic Programming and Nonmonotonic Reasoning (LPNMR'26), Doctoral Consortium
• The 49th German Conference on Artificial Intelligence (KI'26)
• Workshop on Modularity and Splitting Techniques for Knowledge Representation and Reasoning (MOST'26)
• The Sixth International Workshop on Systems and Algorithms for Formal Argumentation (SAFA'26)
• Workshop on Logical Approaches to Handling Inconsistent Data (LINDA'26)
• The 35th International Joint Conference on Artificial Intelligence (IJCAI-ECAI'26), Senior Program Committee member
• The 23rd International Conference on Principles of Knowledge Representation and Reasoning (KR'26)
• The 25th International Conference on Autonomous Agents and Multiagent Systems (AAMAS'26)
• The 40th AAAI Conference on Artificial Intelligence (AAAI'26), Senior Program Committee member
• The 22nd International Conference on Principles of Knowledge Representation and Reasoning (KR'25)
• The Second International Workshop on Argumentation and Applications (Arg&App'25)
• Workshop on Foundations and Future of Change in Artificial Intelligence (FCAI'25)
• The 28th European Conference on Artificial Intelligence (ECAI'25)
• The 4th International Workshop on Process Management in the AI era (PMAI'25)
• The 19th European Conference on Logics in Artificial Intelligence (JELIA'25)
• The First European Workshop on Argumentation and Uncertainty (ArgU'25)
• The First International Workshop on Inconsistency Measurement (IM'25)
• The 48th German Conference on Artificial Intelligence (KI'25)
• The 6th International Conference on Logic and Argumentation (CLAR'25)
• The 34th International Joint Conference on Artificial Intelligence (IJCAI'25), Area chair
• The 39th AAAI Conference on Artificial Intelligence (AAAI'25), Senior Program Committee member
• The 21st International Conference on Principles of Knowledge Representation and Reasoning (KR'24), Area chair
• The Fifth Workshop on Explainable Logic-Based Knowledge Representation (XLoKR'24)
• The 17th International Conference on Logic Programming and Nonmonotonic Reasoning (LPNMR'24)
• The 47th German Conference on Artificial Intelligence (KI'24)
• The 10th Workshop on Formal and Cognitive Reasoning (FCR'24)
• The 3rd International Workshop on Process Management in the AI era (PMAI'24)
• The 10th International Conference on Computational Models of Argument (COMMA'24)
• The 33rd International Joint Conference on Artificial Intelligence (IJCAI'24), Senior Program Committee member
• The 27th European Conference on Artificial Intelligence (ECAI'24)
• The Fourth International Workshop on Logics for New-Generation Artificial Intelligence (LNGAI'24)
• The 14th International Conference on the Theory and Application of Diagrams (DIAGRAMS'24)
• The 38th AAAI Conference on Artificial Intelligence (AAAI'24), Senior Program Committee member
• The 1st International Conference on Recent Advances in Robust Argumentation Machines (RATIO'24)
• The First International Workshop on Argumentation and Applications (Arg&App'23)
• Workshop on Graphical Reasoning with Imperfect Data (GRID'23)
• The 9th Workshop on Formal and Cognitive Reasoning (FCR'23)
• The 46th German Conference on Artificial Intelligence (KI'23), Doctoral Consortium
• The 46th German Conference on Artificial Intelligence (KI'23)
• The 18th European Conference on Logics in Artificial Intelligence (JELIA'23)
• The 20th International Conference on Principles of Knowledge Representation and Reasoning (KR'23)
• The 32nd International Joint Conference on Artificial Intelligence (IJCAI'23), Senior Program Committee member
• The 26th European Conference on Artificial Intelligence (ECAI'23)
• The 37th AAAI Conference on Artificial Intelligence (AAAI'23), Senior Program Committee member
• The 9th Workshop on Argument Mining (ArgMining'22)
• International Workshop on Process Management in the AI era (PMAI'22)
• The 45th German Conference on Artificial Intelligence (KI'22)
• The 15th International Conference on Scalable Uncertainty Management (SUM'22)
• The 9th International Conference on Computational Models of Argumentation (COMMA'22)
• The 16th International Conference on Logic Programming and Nonmonotonic Reasoning (LPNMR'22)
• The Third Workshop on Explainable Logic-Based Knowledge Representation (XLoKR'22)
• The 36th AAAI Conference on Artificial Intelligence (AAAI'22), Senior Program Committee member
• The 31st International Joint Conference on Artificial Intelligence (IJCAI'22)
• The 25th European Conference on Artificial Intelligence (ECAI'22)
• The 21st International Conference on Autonomous Agents and Multiagent Systems (AAMAS'22)
• The First International AIxIA Workshop on Causality (Causal-ITALY'21)
• The 4th International Conference on Logic and Argumentation (CLAR'21)
• The 18th International Conference on Principles of Knowledge Representation and Reasoning (KR'21)
• The 19th International Workshop on Non-Monotonic Reasoning (NMR'21)
• The 16th European Conference on Symbolic and Quantitative Approaches to Reasoning with Uncertainty (ECSQARU'21)
• The 44th German Conference on Artificial Intelligence (KI'21)
• The 30th International Joint Conference on Artificial Intelligence (IJCAI'21), Senior Program Committee member
• The 35th AAAI Conference on Artificial Intelligence (AAAI'21)
• The 20th International Conference on Autonomous Agents and Multiagent Systems (AAMAS'21)
• The 14th International Conference on Scalable Uncertainty Management (SUM'20)
• The 19th International Semantic Web Conference (ISWC'20), Resources Track
• The 17th International Conference on Principles of Knowledge Representation and Reasoning (KR'20)
• The 18th International Workshop on Non-Monotonic Reasoning (NMR'20)
• The 20th EPIA Conference on Artificial Intelligence (EPIA'20), Knowledge Representation and Reasoning Track
• The 43rd German Conference on Artificial Intelligence (KI'20)
• The 8th International Conference on Computational Models of Argumentation (COMMA'20)
• The 29th International Joint Conference on Artificial Intelligence and the 17th Pacific Rim International Conference on Artificial Intelligence (IJCAI-PRICAI'20), Senior Program Committee member
• The 24th European Conference on Artificial Intelligence (ECAI'20), Senior Program Committee member
• The 34th AAAI Conference on Artificial Intelligence (AAAI'20)
• The 2019 International Workshop on Theory and Applications of Formal Argument (TAFA'19)
• The 28th International Joint Conference on Artificial Intelligence (IJCAI'19), *Distinguished Program Committee member*
• The 42nd German Conference on Artificial Intelligence (KI'19)
• The 19th EPIA Conference on Artificial Intelligence (EPIA'19), Knowledge Representation and Reasoning Track
• The 18th International Conference on Autonomous Agents and Multiagent Systems (AAMAS'19), Senior Program Committee member
• The 15th European Conference on Symbolic and Quantitative Approaches to Reasoning with Uncertainty (ECSQARU'19)
• The 33rd AAAI Conference on Artificial Intelligence (AAAI'19)
• The 15th International Conference on Logic Programming and Nonmonotonic Reasoning (LPNMR'19)
• The 17th International Workshop on Non-Monotonic Reasoning (NMR'18)
• The 16th International Conference on Principles of Knowledge Representation and Reasoning (KR'18)
• The 7th International Conference on Computational Models of Argumentation (COMMA'18)
• The 41st German Conference on Artificial Intelligence (KI'18)
• The 1st Workshop on Actors, Agents, Assistants, Avatars (4A'18)
• The 27th International Joint Conference on Artificial Intelligence (IJCAI'18) and the 23rd European Conference on Artificial Intelligence (ECAI'18)
• The Web Conference 2018 (WWW'18), Journal Track
• The Second Chinese Conference on Logic and Argumentation (CLAR'18)
• The 32nd AAAI Conference on Artificial Intelligence (AAAI'18)
• The 32nd AAAI Conference on Artificial Intelligence (AAAI'18), Student Abstract and Poster Track
• Knowledge Representation and Reasoning Track at the 33rd Annual ACM Symposium on Applied Computing (KRR@SAC'18)
• The 6th Workshop on Dynamics of Knowledge and Belief (DKB'17) and the 5th Workshop KI and Kognition (KIK'17)
• The 16th International Semantic Web Conference (ISWC'17)
• The 20th Conference on Principles and Practice of Multi-Agent Systems (PRIMA'17)
• The 2017 International Workshop on Theory and Applications of Formal Argument (TAFA'17)
• The 11th Workshop on Agent Based Computing: From Model to Implementation (ABC:MI'17)
• The 26th International Joint Conference on Artificial Intelligence (IJCAI'17), Senior Program Committee member
• The 26th International Joint Conference on Artificial Intelligence (IJCAI'17), Sister Conference Best Paper Track
• The 18th EPIA Conference on Artificial Intelligence (EPIA'17), Knowledge Representation and Reasoning Track
• The 31th AAAI Conference on Artificial Intelligence (AAAI'17), Student Abstract and Poster Track
• The 30th International FLAIRS Conference - Uncertain Reasoning Track (FLAIRS'17)
• Special Track on Applications of Argumentation at the 30th International Conference on Industrial, Engineering, Other Applications of Applied Intelligent Systems (IEA/AIE'17)
• Knowledge Representation and Reasoning Track at the 32nd Annual ACM Symposium on Applied Computing (KRR@SAC'17)
• The 39th German Conference on Artificial Intelligence (KI'16)
• The 22nd European Conference on Artificial Intelligence (ECAI'16)
• The 12th International Workshop on Uncertainty Reasoning for the Semantic Web (URSW'16)
• The 15th International Semantic Web Conference (ISWC'16)
• The 14th German Conference on Multiagent System Technologies (MATES'16)
• The 14th German Conference on Multiagent System Technologies (MATES'16), PhD Mentoring Track
• The 6th International Conference on Computational Models of Argumentation (COMMA'16)
• The 13th Extended Semantic Web Conference (ESWC'16), Poster track
• The 16th International Workshop on Non-Monotonic Reasoning (NMR'16)
• The 15th International Conference on Principles of Knowledge Representation and Reasoning (KR'16)
• The First Chinese Conference on Logic and Argumentation (CLAR'16)
• The 29th International FLAIRS Conference - Uncertain Reasoning Track (FLAIRS'16)
• The 15th International Conference on Autonomous Agents and Multiagent Systems (AAMAS'16)
• The 30th AAAI Conference on Artificial Intelligence (AAAI'16), Student Abstract and Poster Track
• The 1st International Workshop on LINKed EDucation (LINKED'15)
• The 13th European Conference on Multi-Agent Systems (EUMAS'15)
• The 18th Conference on Principles and Practice of Multi-Agent Systems (PRIMA'15)
• The 11th International Workshop on Uncertainty Reasoning for the Semantic Web (URSW'15)
• The 38th German Conference on Artificial Intelligence (KI'15)
• The 5th Workshop on Dynamics of Knowledge and Belief (DKB'15) and the 4th Workshop KI and Kognition (KIK'15):
• The 24th International Joint Conference on Artificial Intelligence (IJCAI'15)
• 1st Workshop on Belief Change and Non-Monotonic Reasoning in Ontologies and Databases (JOWO'15)
• The 2015 International Workshop on Theory and Applications of Formal Argument (TAFA'15)
• The Third Workshop on Weighted Logics for AI (WL4AI'15)
• The 14th International Semantic Web Conference (ISWC'15)
• The 4th IFIP International Conference on Artificial Intelligence in Theory and Practice (AITP'15)
• The 12th Extended Semantic Web Conference (ESWC'15), Poster track
• The 12th Extended Semantic Web Conference (ESWC'15), PhD symposium
• The 13th German Conference on Multiagent System Technologies (MATES'15), Doctoral Consortium
• The 13th German Conference on Multiagent System Technologies (MATES'15)
• The 14th International Conference on Autonomous Agents and Multiagent Systems (AAMAS'15)
• IWCS Workshop: Language and Ontologies
• The 10th Workshop on Agent Based Computing: From Model to Implementation (ABC:MI'15)
• The 9th IEEE International Conference on Semantic Computing (ICSC'15)
• The 29th AAAI Conference on Artificial Intelligence (AAAI'15)
• The 29th AAAI Conference on Artificial Intelligence (AAAI'15), Student Abstract and Poster Track
• The 12th European Conference on Multi-Agent Systems (EUMAS'14)
• The 10th International Workshop on Uncertainty Reasoning for the Semantic Web (URSW'14)
• The 37th German Conference on Artificial Intelligence (KI'14)
• The 21st European Conference on Artificial Intelligence (ECAI'14)
• The 8th IEEE International Conference on Semantic Computing (ICSC'14)
• The Twelfth German Conference on Multiagent System Technologies (MATES'14), Doctoral Mentoring Track
• The Twelfth German Conference on Multiagent System Technologies (MATES'14)
• The Second Workshop on Social News on the Web (SNOW'14)
• The Empirical 2014 workshop (Empirical'14)
• The 11th Extended Semantic Web Conference (ESWC'14)
• 15th International Conference on Information Processing and Management of Uncertainty in Knowledge-Based Systems (IPMU'14), Special Session on Uncertainty and Imprecision on the Web of Data
• The 28th AAAI Conference on Artificial Intelligence (AAAI'14), Student Abstract and Poster Track
• The 9th International Workshop on Uncertainty Reasoning for the Semantic Web (URSW'13)
• The 4th Workshop on Dynamics of Knowledge and Belief (DKB'13)
• The 7th IEEE International Conference on Semantic Computing (ICSC'13)
• The 23rd International Joint Conference on Artificial Intelligence (IJCAI'13)
• The 10th Workshop on Nonmonotonic Reasoning, Action and Change (NRAC'13)
• The 27th AAAI Conference on Artificial Intelligence (AAAI'13), Student Abstract and Poster Track
• The 26th International FLAIRS Conference (FLAIRS'13)
• The 8th International Workshop on Uncertainty Reasoning for the Semantic Web (URSW'12)
• The 6th IEEE International Conference on Semantic Computing (ICSC'12)
• The 6th Starting Artificial Intelligence Research Symposium (STAIRS'12)
• The 25th International FLAIRS Conference (FLAIRS'12)
• The 26th AAAI Conference on Artificial Intelligence (AAAI'11), Student Abstract and Poster Track
• The 3rd Workshop on Dynamics of Knowledge and Belief (DKB'11)
• The 22nd International Joint Conference on Artificial Intelligence (IJCAI'11)
• The 24th International FLAIRS Conference (FLAIRS'11)

Other reviewing activities

• Argument and Computation (A&C)
• Artificial Intelligence (AIJ)
• Discrete Applied Mathematics (DAM)
• Fundamenta Informaticae (FI)
• Fuzzy Sets and Systems (FSS)
• IfCoLog Journal of Logics and their Applications (FLAP)
• Information and Computation (I&C)
• International Journal of Approximate Reasoning (IJAR)
• International Journal on Semantic Web and Information Systems (IJSWIS)
• Journal of Applied Non-Classical Logics
• Journal of Artificial Intelligence Research (JAIR)
• Journal of Autonomous Agents and Multi-Agent Systems (JAAMAS)
• Journal of Logic and Computation (JLC)
• Künstliche Intelligenz (KUIN)
• Studia Logica
• Theory and Practice of Logic Programming (TPLP)
• Logica Universalis

Other memberships and roles

• 2025-now: President of the steering committee of the International Conference on Computational Models of Argument (COMMA)
• 2025-now: Chair of the steering committee of the International Workshops on Nonmonotonic Reasoning (NMR)
• 2025-now: Member of the publicity committee of Principles of Knowledge Representation and Reasoning (KR), Inc
• 2025-now: Member of the steering committee of Principles of Knowledge Representation and Reasoning (KR), Inc
• 2025-now: Member of the steering committee of the European Conferences on Symbolic and Quantitative Approaches to Reasoning with Uncertainty (ECSQARU)
• 2023-now: Member of the steering committee of the International Workshops on Nonmonotonic Reasoning (NMR)
• 2021-now: Member of the editorial board of Artificial Intelligence
• 2021-now: Member of the editorial board of Theoretical Computer Science in Frontiers in Computer Science
• 2017-now: Member of the steering committee of the International Conference on Computational Models of Argument
• 2016-now: Member of the editorial board of Argument & Computation
• 2021-2024: Secretary of the steering committee of the International Conference on Computational Models of Argument
• 2015-2023: Member of the steering committee of the International Competition on Computational Models of Argumentation
• 2017-2023: Co-chair of the special interest group Knowledge representation and reasoning of the technical committee Artificial Intelligence of the German Computer Science Association
• 2015-2023: Chairman of the working group Knowledge representation and reasoning of the International Federation for Information Processing, Technical Committee on Artificial Intelligence
• 2020-2023: IFIP TC "Artificial Intelligence" representative in the German IFIP Advisory Board
• 2015-2019: President of the steering committee of the International Competition on Computational Models of Argumentation

Administrative activities

• 2026-now: Dean of the department of "Mathematics and Computer Science" at the University of Hagen
• 2024-now: Substitute member of the general examination committee of the faculty "Mathematics and Computer Science" at the University of Hagen
• 2022-now: Substitute member of the PhD committee of the faculty "Mathematics and Computer Science" at the University of Hagen
• 2022-now: Member of the rectorate committee for research and the fostering of young talent at the University of Hagen
• 2025-2026: Chair of the study advisory board of the department of "Mathematics and Computer Science" at the University of Hagen
• 2025-2026: Chair of the study planning and evaluation committee of the department of "Mathematics and Computer Science" at the University of Hagen
• 2025-2026: Dean of studies of the department of "Mathematics and Computer Science" at the University of Hagen
• 2022-2026: Chair of the habilitation committee "Mathematics and Computer Science" at the University of Hagen
• 2024-2026: Substitute member of the unversity committee on quality improvement in teaching at the University of Hagen
• 2025-2025: Vice-dean of the department of "Mathematics and Computer Science" at the University of Hagen
• 2022-2025: Member of the faculty council "Mathematics and Computer Science" at the University of Hagen
• 2022-2024: Substitute member of the examination committee of computer science of the faculty "Mathematics and Computer Science" at the University of Hagen
• 2017-2020: Member of the computer science teaching committee at the University of Koblenz-Landau
• 2014-2020: Member of the computer science faculty council at the University of Koblenz-Landau
• 2012-2019: Ombudsman for PhD students at Institute for Web Science and Technologies at University of Koblenz-Landau
• 2014-2016: Member of the computer science PhD committee at the University of Koblenz-Landau
• 2009-2011: Vice-spokesman for research assistants in computer science at TU Dortmund
• 2008-2011: Initiator and organizer of a bi-weekly postgraduate seminar at TU Dortmund (see Promovenden-Kolloquium (intern))
• 2007-2011: Study advisor at TU Dortmund (see homepage of study advisors)