6Chu Y P. A mathematical model to evaluate a CAI courseware. Mathematical and Computer Modell, 1996,27 (2) : 95.
7de v Steyn M M, Alexander P M, Rohm D. CAL for first year analytical chemistry by distance education. Computers Education, 1996,27 (2) : 95.
8Ki-Sang Song, Hu Xiangen, Andrew Olney,et al. A framework of synthesizing tutoring conversation capability with web-based distance education eourseware. Computers & Education, 2004,42(4) : 375.
