- Co-organiser (with Christoph Beierle) of the "Uncertain Reasoning" Track at FLAIRS'13.

   - Co-editor (with Carmel Domshlak, Eyke Hüllermeier and Henri Prade) of a special issue "Representing, Learning, and Processing Preferences: Theoretical and Practical Challenges" in Artificial Intelligence, 175(7-8), 1037-1052, 2011.

   - Co-organiser (with Lluis Godo) of the session "Fuzzy Preference Modeling and Preferences in AI: two sides of the same coin" at IPMU'10.

Program Committee

   - International Joint Conference on Artificial Intelligence, IJCAI'13
   - Autonomous Agents and Multiagent Systems, AAMAS'13
   - Multidisciplinary Workshop on Advances in Preference Handling (in conjunction with ECAI), MPREF'12
   - Weighted Logics for AI (in conjunction with ECAI), WL4AI'12
   - Florida Artificial Intelligence Research Society, FLAIRS'12
   - Senior Programme Committee of the International Joint Conference on Artificial Intelligence, IJCAI'11
   - Uncertainty in Artificial Intelligence, UAI'11
   - Florida Artificial Intelligence Research Society, FLAIRS'11
   - International Conference on Electronic Commerce and Web Technologies, EC-Web'11
   - Colloque sur l'Optimisation et les Systèmes d'Informations, COSI'11
   - Conference on Artificial Intelligence, AAAI'10
   - European Conference on Artificial Intelligence, ECAI'10
   - International Conference on Electronic Commerce and Web Technologies, EC-Web'10
   - Workshop on Logics for Intelligent Agents and Multi-Agent Systems, WLIAMAS'10
   - Reconnaissance des Formes et Intelligence Artificielle, RFIA'10
   - Colloque sur l'Optimisation et les Systèmes d'Informations, COSI'10
   - IEEE International Conference on Cybernetics Intelligent Systems, CIS'09
   - Colloque sur l'Optimisation et les Systèmes d'Informations, COSI'09
   - Autonomous Agents and Multiagent Systems, AAMAS'08
   - Australian Joint Conference on Artificial Intelligence, AI'07
   - Rencontres Jeunes Chercheurs en Intelligence Artificielle, RJCIA'05
   - Uncertainty in Artificial Intelligence, UAI'04
   - Uncertainty in Artificial Intelligence, UAI'03

Referee for

   - International Conference on Computational Models of Argument, COMMA'10
   - International Joint Conference on Artificial Intelligence, IJCAI'07
   - European Conference on Artificial Intelligence, ECAI'06
   - International Joint Conference on Artificial Intelligence, IJCAI'05
   - Intelligent Agent Technology, IAT'05
   - European Conference on Artificial Intelligence, ECAI'04
   - European Conference on Logics in Artficial Intelligence, JELIA'04
   - International Workshop on Non-Monotonic Reasoning, NMR'04
   - Journal of Artificial Intelligence Research
   - Artificial Intelligence
   - International Journal of Approximate Reasoning
   - Annals of Mathematics and Artificial Intelligence
   - Logic Journal of the Interest Group in Pure and Applied Logic
   - International Journal of Intelligent Systems
   - International Journal on Information Fusion
   - International Journal of Information Science
   - Journal of Discrete Applied Mathematics