Kostas Stefanidis is a PhD candidate in the Department of Computer Science at the University of Ioannina. He received his MSc degree in 2005 and his BSc degree in 2003 from the University of Ioannina, both in Computer Science. From 2002 until now, he is a member of the Distributed Data Management Laboratory. His research interests focus on personalization systems, with particular interest in personalized search. His current work focuses on defining and managing context-dependent preferences, and on personalized search in distributed settings such in peer-to-peer and publish-subscribe systems. He also holds a postgraduate research scholarship for pursuing his Phd given by the Greek Ministry of Education PENED 03-ED-591.