1Rumble, G. (1997) . The Costs and Economics of Open and Distance Learning[M] . London: Kogan Page .
2Bartolic-Zlomislic, S. & Bates, A.W. (1999) . Assessing the Costs and Benefits of TeleLearning: A Case Study from the University of British Columbia[OL] . From http://det.cstudies.ubc.ca/detsite/researchproj.htm
3Brian M. Morgan . Is Distance Learning Worth It? Helping to Determine the Costs of Online Courses[OL] . from http://webpages.marshall.edu/～morgan 16/onlinecosts/
4Bartolic-Zlomislic, Silvia & Bates, A. W. (1999) . Investing in online learning: potential benefits and limitations[J].Canadian Journal of Communication, (24) : 349-366 .
5Butschler, M. & Bartolic-Zlomislic, S. (1999) . Assessing the Costs and Benefits of TeleLearning: A Case Study from the Department of Distributed Learning & Employee Development, Kwantlen University College[OL] . From http://det.cstudies.ubc.ca/detsite/researchproj.htm.
6Bartolic-Zlomislic, S. & Bates, A.W. (1999) . Assessing the Costs and Benefits of TeleLearning: A Case Study from the University of British Columbia[OL] . From http://det.cstudies.ubc.ca/detsite/researchproj.htm
7Butschler, M. & Bartolic-Zlomislic, S. (1999) . Assessing the Costs and Benefits of TeleLearning: A Case Study from the Department of Distributed Learning & Employee Development, Kwantlen University College[OL] . From http://det.cstudies.ubc.ca/detsite/researchproj.htm.
8Downes, Stephen (1998) . The economics of online learning[OL] . Retrieved February 17, 2000 . From:http://www. atl.ualberta.ca/downes/future/economics.htm.
9Ben Shneiderman,Ellen Yu Borkowski,Maryam Alavi,Kent Norman. Emergent patterns of teaching/learning in electronic classrooms[J] 1998,Educational Technology Research and Development(4):23～42
10James Laffey,Thomas Tupper,Dale Musser,John Wedman. A computer-mediated support system for project-based learning[J] 1998,Educational Technology Research and Development(1):73～86
