This contribution is an attempt to systematise our approach to the design of a virtual campus. Activities in the recently started TECFA virtual campus rely on Internet tools, but they concern both distance teaching and presential interactions. Designing learning activities is relatively easy when the learning goal is an activity in itself. In this contribution, we explain how we extend the “learning by doing” approach to the acquisition of declarative knowledge. After fulfilling a pseudo-task, the activities we describe lead students to interpret a graphical representation of their performance. This happens during a debriefing session where the teacher turns students’ experiential knowledge into academic knowledge. The target knowledge, i.e. the concept or theory we want them to understand, is acquired through the effort students make to understand differences that appear in the representation of pseudo-task performances. The representations produced by the system were successful in triggering intense discussions.