J. Allwood, J. Nivre, and E. Ahlsén, On the Semantics and Pragmatics of Linguistic Feedback (Gothenburg Papers in Theoretical Linguistics No. 64), 1991.

M. Baker, T. Hansen, R. Joiner, and D. Traum, The role of grounding in collaborative learning tasks Collaborative learning. Cognitive and computational approaches Advances in Learning and Instruction Series, pp.31-63, 1999.

S. E. Brennan, The grounding problem in conversations with and through computers, Social and cognitive approaches to interpersonal communication. Mahwal, NJ: Erlbaum, pp.201-225, 1998.

P. Dillenbourg, Introduction: What do you mean by " collaborative learning Collaborative learning. Cognitive and computational approaches Advances in Learning and Instruction Series, pp.1-19, 1999.

N. Hara, C. J. Bonk, and C. Angeli, Content analysis of online discussion in an applied educational psychology course, Instructional Science, vol.28, issue.2, pp.115-152, 2000.
DOI : 10.1023/A:1003764722829

S. Järvelä and P. Häkkinen, in press) The levels of web-based discussions ? using perspective-taking theory as an analysis tool, Cognition in a digital world, 2001.

M. Saarenkunnas, S. Järvelä, P. Häkkinen, L. Kuure, P. Taalas et al., NINTER ? Networked Interaction: Theory-based cases in teaching and learning, Learning Environments Research, vol.3, issue.1, pp.35-50, 2000.
DOI : 10.1023/A:1009970902424