Our research aims at observing a distant collaborative mediated learning situation. In the activity we study, two actors are asked to co-conceive a procedural text with the help of three types of resources: a video showing actions to describe, a chat and a text editor. During this activity, traces become visible. Traces concern interactions between participants and interactions between participants and artefacts. We qualify properties of traces and their uses, and we show that traces' mobilisation by participants brings activity's distribution to light.