3Jyothi, S., McAvinia, C., & Keating, J. A visualisation tool to aid exploration of students'interactions in a- synchronous online communication [ J ]. Computer &Education, 2012,58:30 - 42.
4Welser, H.T., Gleave, E., Fisher, D., et al. Visualizing the signatures of social roles in online discussion groups [ J ]. Journal of Social Structure, 2007,8 ( 2 ).
5Sheard, J., Albrecht, D., & Butbul, E. Vi- SION: Visualizing student interactions online[A]. The Eleventh Australasian World Wide Web Conference ( AusWeb05 ) [ C ]. Queensland, Australia :2005.
6Janssen, J., Erkens, G., & Kanselaar, G. Vi- sualization of agreement and discussion processes during comput- er- supported collaborative learning[ J ]. Computers in Human Behavior,2007,23 : 1105 - 1125.
7Mazza, R. Visualization in Educational Environments~ A]. Handbook of Educational Data Mining E C 1. Minnesota : CRC Press,2010.9 - 26.
8Eppler, M.J., & Burkard, R. A. Knowledge Visual- ization : Towards a New Discipline and its Fields of Applica- tion, ICA Working Paper#2/2004 [ R]. University of Lugano, 2004.
9Daly, A.J. , Moolenaar, N. , Bolivar, J. M. , et al. Relationships in reform : The role of teachers" social networks [ J ]. Journal of Educational Administration, 2010, 48 (3) : 359 - 391.
10Sheridan, D. , & Witherden, S. Visualising and in- ferring LMS discussions [ A]. In ICT: Providing choices for learners and learning [ C ]. Singapore : ASCILITE, 2007.1134 - 1139.