6Shute, V. J. & Psotka, J. Intelligent tutoring systems: Past, present, and future[A]. D. H. Jonassen (Ed.), Handbook of Research for Educational Communications and Technology[C]. New York: Macmillan. 1996:570-600.
7Bloom, B.S. The 2 Sigma Problem: The Search for Methods of Group Instruction as Effective as One-to-One Tutoring [J]. Educational Researcher, 1984,(13): 3-16.
8Loftin, R. B., Kenney, P., & Mastaglio, T. Outstanding Research Issues in Intelligent Tutoring Systems [DB/OL].http://www. mymicsurveys.com/site/files/pub_4.pdf.
9Lane, H. Chad.Intelligent Tutoring Systems: Prospects for Guided Practice and Efficient Learning [R].Whitepaper for the Army's Science of Learning Workshop, Hampton, VA., 2006.
10Murray, T., Blessing, S., & Ainsworth, S. (Eds.) Authoring Tools for Advanced Technology Learning Environments: Toward Costeffective Adaptive, Interactive and Intelligent Educational Software [M].Norwell, MA: Kluwer Academic Publishers,2003.