programme committee member of AAMAS 2009.

programme committee member of eHealth 2009.

PIPS (Personalised Information Platform for Life and Health Services), a EU FP6 integrated project in the area of e-Health

programme committee member of the Symposium on Affective Language in Human and Machine, in conjunction with the AISB 2008 Convention.

invited participant to the workshop “Designing digital interventions to help overcome addictive behaviours” at Cumberland Lodge, Windsor, UK, 7-9 May 2008

programme committee member of the 2nd International Conference on Computational Models of Argument (COMMA08)

invited participant to the Perspectives Workshop: Theory and Practice of Argumentation Systems, Schloss Dagstuhl, 2008.

guest editor, with Chris Reed, of a Special Issue of the International Journal of Intelligent Systems on Computational Models of Natural Argument (Volume 22, No. 1, January 2007).

invited participant to the workshop Modelling Meetings, Argumentation & Discourse, 2006.

programme committee member of the 1st International Conference on Computational Models of Argument (COMMA06)

organising committee member of the AAAI 2006 Spring Symposium on Argumentation for Consumers of Healthcare.

programme committee member of the 2nd SEMANTIC WEB TECHNOLOGY FOR MOBILE AND UBIQUITOUS APPLICATIONS, in conjunction with ECAI 2006.

programme committee member of the Healthcare Digital Libraries Workshop 2005

programme committee member of the Special Track on User Modeling and HCI Approaches in Natural Language Generation at FLAIRS 2004.

programme committee member of the SEMANTIC WEB TECHNOLOGY FOR MOBILE AND UBIQUITOUS APPLICATIONS, in conjunction with ISWC04, 2004.

programme committee member of the Workshop on Attitude, Personality and Emotions in User-Adapted Interaction, in conjunction with UM 2001

invited participant to the  Symposium on Argument and Computation, 2000

programme committee member of the Doctoral Consortium Session, 7th International Conference on User Modelling, 1999