It is assumed that cooperative learning continuously constructs and extends the shared knowledge of a group of learners with respect to a specific learning domain. Experiences with Computer-Supported Collaborative/Cooperative Learning (CSCL) environments indicate that an explicit representation of the shared knowledge is helpful with regard to two aspects: First, it can preserve (intermediate) results of the cooperative learning process. Second, it can also improve the process itself by providing the context and means for learners' orientation and navigation in the learning domain, awareness of the learning process, and the construction and negotiation of knowledge. In this paper, we introduce the Learning Net as an interactive representation of shared knowledge and sketch how it can be integrated and used in a CSCL environment.