Since January 2008 I am the Editor-in-Chief of  Information Processing and Management (IPM), published by Elsevier;

Since June 2009 I am an Associate Editor of ACM Transactions of Intelligent Systems and Technology (TIST).

I am (or was) a member of the Editorial Board of the following journals:

and I review papers for several other journals, including ACM TOIS, IEEE TKDE, JIR, ACM TOCHI,  and others.

I have been a General Chair or Program Chair of several conferences, including ECIR 2002, CoLIS 2005, SPIRE 2006, SIGIR 2010, ICTIR 2011, and ICADL 2011. Also, I am regularly a member of the Program Committee of several conferences, including: SIGIR, ECIR, CIKM, ECDL, ICADL, SPIRE, IIR, etc.

I am a member of the college of reviewers for project proposals submitted to EPSRC, SNSF, EU-FP7, Science Foundation Ireland, Singapore Science Foundation, etc.

I am external reviewer of the Department of Multimedia of the University of Putra (Malaysia).