Scripts structure the collaborative learning process by constraining interactions, defining a sequence of activities and specifying individual roles and by. Scripts aim at increasinghe probability that collaboration triggers knowledge generative interactions such as conflict resolution, explanation or mutual regulation. Integrative scripts are not bound to collaboration in small groups but include individual activities and class-wide activities. These preand post-structuring activities form the didactic envelope of the script. In many cases, the core part of the script is based on one among a few schemata: Jigsaw, conflict, reciprocal. We propose a model for designing this core component. This model postulates that learning results from the interactions that students engage in to build a shared understanding of a task despite the fact that it is distributed. Hence, the way the task is distributed among group members determines the interactions they will engage in. Interactions are viewed as the mechanisms for overcoming task splits. A large variety of scripts can be built from a small number of schemata, embedded within activities that occur across multiple social planes, activities which are integrated with each other by few generic operators.