Peter has been working in the field of adaptive educational systems, user modeling, and intelligent user interfaces for more than 20 years. He published numerous papers and edited several books on adaptive hypermedia and the adaptive Web. He was holding visiting faculty appointments at the Moscow State University (Russia), Sussex University (UK), Tokyo Denki University (Japan), University of Trier (Germany), Free University of Bolzano (Italy), National College of Ireland, and Carnegie Mellon University.