When proposing group activities to students with a view to fostering collaborative learning in a hybrid learning space, we often ourselves about the relative amounts of information and knowledge which flow in the interaction, both among the group members and from the external information and knowledge sources. Also about which stages of the collaborative process have the highest indexes of knowledge flow and information flow, respectively. The experiment described below has tried to answer these questions. It involved 66 students from the University of Turin who, after receiving a lecture on online communities of professionals and some suggestions for basic reading, were asked to collectively develop an artefact (specifically, a wiki) which would summarise what had been learnt. Both in the study phases, and in the phases of the structuring and collaborative development of the artefact, the students were asked to provide a quantitative and qualitative estimate of the information and knowledge flows characterising the different stages of the experiment. It emerged that the stages of study and structuring of the artefact were those with the highest knowledge flow index, while in the actual writing of the artefact there was a predominance of information flows.