Abstract
In many dynamic situations, which are highly goal directed and temporally constrained, most of the cooperation difficulties (e g., problems between humans and automation) can be reasonably addressed by adopting a cognitive viewpoint. Cooperation is taken as the management of interference between individual activities to facilitate the team members' subtasks and the team's common task when there is one. Thus, planning models are of great relevance in identifying cooperation difficulties and supporting cooperative activities. Studies on individual activity in dynamic situations have stressed the importance of the elaboration and maintenance of a current representation of the situation, (an extension of situation awareness). The concept of Cofor (common frame of reference) generalises this idea to teams. Two series of results drawn from rapid process control situations where there is insufficient time to converse at length (air traffic control and double seat fighter aircraft) show that Cofor activities are first invested into the recall and confirmation of plan, task allocation, and decisions at key points before action completion The investment in prevention reduces the risk of fatal interference, or missed action