In this study, we present an educational design experiment seeking to promote interaction and knowledge sharing in groups and to establish a sense of community among students during a semester at Aalborg University, Denmark. The experiment is materialised as a tangible artefact in the form of a colourful box with materials and texts. Some of the materials are oriented towards supporting the collaborative activities taking place in the group, while others are intended to support individual groups in displaying a visual identity and the public historical trajectory of their problem-based learning process to other groups or peers. The lessons learned from the experiment highlight that educational designs are difficult to implement in practice if it is not mandatory for the students, teachers and supervisors to take part. Furthermore, we imagined the box as a toolbox to support process-related aspects of problem-based learning, such as collaborative interaction, problem formulation and the collaborative learning process itself, whereas the students requested specific 'how to' materials for certain project activities -- focusing more on the semester product and the outcome of problem-based learning.