In order to ensure that group work fulfills its didactic purpose – namely „to enhance members‘ educational development“ (Birmingham/McCord 2002, p. 73) – a sophisticated concept is required. The effect of simply inserting a group task into a curriculum can in fact be just the opposite of that which is intended, especially if the goal is for students to learn to work in a team. Whether group work really supports learning depends largely upon the degree of group cohesion. Here, cohesion means the bonding force of group membership or the appeal of the group from the perspective of the individual (cf. Kerres 2013, p. 185). According to Kerres, the realization of this bonding force requires, for one, a task that is considered both interesting by and worthwhile for all members. Meanwhile, the group members must also be able to work well together, and this requires that their relationships are characterized by mutual respect. The latter should facilitate the greatest possible density of interaction. Meanwhile, shared experiences of success as well as a fundamentally competitive orientation of the group task can also aid in the establishment of group cohesion. Now, it is important to consider what kind of group cohesion is also able to fully unlock the group’s potential.
This question leads to a significant problem inherent in short-term group work, which is intended to be used as a tool to “loosen up” the instructional environment: according to Michaelsen, groups must work together for at least 20-25 hours “before they can fully assess and benefit from the resources of all members of the group” (Michaelsen 2002, S. 30). The Tuckman Model explains why this is the case. According to this model, group members must first experience the three phases of forming, storming, and norming before they reach the performance phase. Only then can they work successfully together, cooperate, and quite flexibly exchange roles (for example that of group leadership). At this stage, clear lines of communication exist between group members, they assist one another, and they are able to complete their tasks successfully (cf. Van Dick/West 2013, S. 27).
The fact that groups first have to “mature”, together with the condition that groups should not need to meet outside of normal class sessions in order to complete their tasks (cf. Michaelsen/Knight 2002, S. 57), leads to the previously mentioned, daunting idea that once TBL has been employed, it is impossible to return to a more traditional teaching and learning approach. TBL requires that groups stay together over the long term and solve tasks as often as possible while in the classroom. When one considers the time investment necessary for the establishment of functional and efficient groups, it becomes apparent that students must engage in team-based work for the entirety of the available face-to-face course time. An isolated iteration of TBL which takes place over the course of a single session for the purpose of evaluating the effectiveness of this teaching and learning strategy will thus necessarily fall short of its full potential.