8Gray D. The internet in school [ M ]. London and New York: Cassell, 1999.
9David Jonassen. Constructivism and Computer-Mediated Communication in Distance Education [ J ]. The American Journal of Distance Education, Vol. 9, No. 2, 1995.
10Kafai, Y.. & Resnik, M. Constructivism in practice:Designing, thinking and learning in a digital world[ M].Mahwah, NJ: Lawrence Erlbaum Associations, 1996.