During the spring of 2001 he was a Visiting Researcher at the Statistics Laboratory of the University of Cambridge, UK, and the summer of 2001 and 2006 he was a Research Fellow at British Telecommunications (BT) Labs in Ipswich, UK. Vasilios Siris obtained the Diploma in Physics from the National Kapodistrian University of Athens (1990), and the Masters of Science in Computer Science from Northeastern University, Boston, USA (1992) and the PhD in Computer Science from the University of Crete (1998).