Talk:Trialogue
I revised the previous definition by emphasizing more the role of artefacts, and lessening the role of a "shared understanding" or a "shared belief system". The same issue is a central topic also for learning theories - see:
Paavola, S. & Hakkarainen, K. (2009). From meaning making to joint construction of knowledge practices and artefacts – A trialogical approach to CSCL. In C. O'Malley, D. Suthers, P. Reimann, & A. Dimitracopoulou (Eds.), Computer Supported Collaborative Learning Practices: CSCL2009 Conference Proceedings. (pp. 83-92). Rhodes, Creek: International Society of the Learning Sciences (ISLS).
The idea is that shared understanding is central especially in the tradition of dialogues. It might help also in trialogues, but in trialogues more important are ways of working with external artefacts.