Published on in Vol 17, No 10 (2015): October
1 Department of Computer Science, University of Cyprus, Nicosia, Cyprus
2 STREMBLE Ventures Ltd., Limassol, Cyprus
3 Department of Communication and Internet Studies, Cyprus University of Technology, Limassol, Cyprus
4 Lab of Medical Physics, Medical School, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
5 Department of Teacher Education, University of Helsinki, Helsinki, Finland
6 Dipartimento di Ingegneria Elettrica, Elettronica e Informatica, Università di Catania, Catania, Italy
7 e-Learning Unit (ELU), Division of Population Health Sciences & Education, St George’s, University of London, London, United Kingdom
*these authors contributed equally