6[1]Fulford. C & Zhang. S, Perceptions of interaction: The critical predictor in distance education [ J ]. American Journal of Distance Education. 1993 (3).
7[2]Ibert, L & Moore, D. R. Building interactivity into web coures: tools for social and instructional interaction [ J ]. Educational Technology. 1998 ( 3 ).
8Chanlin L. · Students Cognitive Styles and the Need of Visual Control in Animation · J. of Education Computing Research, 1998; 19 (4): 353-365
