After having read a definition of collaboration on mediaTIC, I would like to give a more general view : Collaboration is a situation that involves two or more persons carrying out a joint activity. Three major features characterise a collaborative situation :

- The peers who collaborate have almost the same level considering the action they can perform, the knowledge and the skills they possess. This means that there must be, more or less, a degree of symmetry in the interactions performed by the participants of a collaborative activity.

- The participants share common goals or a common interest which is the reason of their interaction : performing a task. They also have personal goals (which are their own private motivation).

- There is a division of labour among the participants. Academics often distinguish cooperation and collaboration. The author states that In cooperation, partners split the work, solve sub-tasks individually and then assemble the partial results into the final output. In collaboration, partners work together. Collaboration also concerns the interactions which take place between the participants. First, a collaborative activity implies interactivity. That does not mean that what matters is the amount of interactions. In fact, the extent to which the interactions between group members influence the participants cognitive processes is a more accurate criterion to define the degree of interactivity. It is also often claims that carrying out a joint activity together (i.e. to collaborate) implies synchronous communication (whereas asynchronous communication is often used for cooperation). As a matter of fact, to work synchronously, participants need to interact synchronously. It must be stressed that negotiation is also an important feature during collaboration. Participants discusses, justify, argue and try to convince their partners. We should finally bear in mind that collaboration imply the same cognitive mechanisms as those which operate in individual cognition. Reasoning processes like induction, analogy-based reasoning or self-explanation are used, as well as cognitive load. Several academics have also stressed that collaboration can be seen as a problem solving task. Roschelle and Teasley (1995) state that: collaboration is a coordinated, synchronous activity that is the result of a continued attempt to construct and maintain a shared conception of a problem. They also propose the notion of joint problem space to explain what is going on during collaboration: () Social interactions in the context of problem solving activity occur in relation to a Joint Problem Space (JPS). The JPS is a shared knowledge structure that supports problem solving activity by integrating (a) goals (b) descriptions of the current problem state, (c) awareness of available problem solving actions, and (d) associations that relate goals, features of the current problem state, and available actions." Hence, collaboration is a process of solving a problem and maintaining a shared conception of the situation (the JPS) by integrating information during the task. This understanding of the task is continually shaped and reshaped during the course of the interaction. Consequently, collaborative problem solving cannot only be seen as sharing tasks. As a matter of fact, collaboration implies interactions between participants, the effort of maintaining a shared understanding of the situation and taking into account the aims and the expectations of the group.

Building this shared conception can be carried out by:

- The possibility of introducing new information to the shared representation of the problem.

- The fact that the participants can be aware of the possible divergence of opinion or representations.

- The possibility of repairing those divergences of representations. Therefore, a collaborative technology must provide tools for supporting those functionalities. Unfortunately, computer-mediated collaboration has not kept up with the needs for people to effectively perform collective tasks. Working or playing together in a virtual environment has revealed the tremendous lack of human interactions that occur in co-located activities. That is why distributed teams (of players or workers) create a need for collaboration support