Thanks a lot Cristina, I found them very useful, I will check your references in my University's Dabatabase. I have also reviewed these three books, you can (partially) read them using Google Books: Flink, Arlene (2002) How to Ask Survey Questions Sage Publications Hine, Christine (2005)  Virtual methods: issues in social research on the Internet Berg Publishers Sue, Valerie (2008)  Conducting Online Surveys Sage Publications ------------------------ Hi Michael,  Maybe you can find something useful in these books: -              Garton, L., C. Haythornthwaite and B. Wellman (1999) ‘Studying On-Line Social Networks’, in S.G. Jones (ed.) Doing Internet Research: Critical Issues and Methods for Examining the Net, pp. 75–106. Thousand Oaks, CA:                           SAGE. -              Gunter, B., D. Nicholas, P. Huntington and P. Williams (2002) ‘Online Versus Offline Research: Implications for Evaluating Digital Media’, Aslib Proceedings -              Jones, S.G. (ed.) (1999) Doing Internet Research: Critical Issues and Methods for Examining the Net. Thousand Oaks, CA: SAGE. -              Leece, P., M. Bhandari, S. Sprague, M. Swiontkowski, E. Schemitsch, P. Tornetta, P. Devereaux and G. Guyatt (2004) ‘Internet Versus Mailed Questionnaires: A Randomized Comparison’, Journal of Medical Internet Research -              Moss, J. and G. Hendry (2002) ‘Use of Electronic Surveys in Course Evaluation’, British Journal of Educational Technology -              Van Selm, M. and N.W. Jankowski (2006) ‘Conducting Online Surveys’, Quality and Quantity Cheers,  Cristina Miguel  Msc Interactive Digital Communication Universidad de Vic Sagrada Familia, 7 08500 Vic (Barcelona) www.uvic.cat