Résumé
The current global dimension of human exchanges in any domain (work, commerce, learning, entertainment...) is accompanied by technologies that enhance synchronous and asynchronous communication thus facilitating both collaboration and competition: the two driving forces for progress since ages. Collaboration can be made essentially in asynchronous mode by e-mails, files and information exchanges, or in synchronous mode by organizing meetings where collaborators communicate directly. Geographical and temporal distance may be overcome by several ICT (Information and Communication Technologies) solutions, usually under the label of e-collaboration. This concept is based on a high number of interactions that could be classified in three types: Computer to Computer Interaction (1), Collaborator to Computer Interaction (2) and Collaborator to Collaborator Interaction (3). Consequently, performance evaluation of e-collaboration has to be considered as consisting separately on the evaluation of each of the three types of interaction. This view leads to focus on three main aspects: the first is the system -efficiency- the second is the interface -ergonomics- the third is the collaborator's behavior during collaboration and its influence on the outcome of the joint effort -effectiveness. Three evaluation layers are so found. In this paper, we propose an appropriate evaluation method to each layer, so that future developments, applying the new evaluation method and exploiting results in actual settings, may improve separately efficiency, ergonomics and effectiveness of e-collaboration in a complementary way.