This article addresses evolutionary design in the context of e-learning devices. It proposes a design approach that takes into account the changing behaviours and needs of different actors (tutors, authors and learners) in order to evolve and adapt a training device to real practices. For this, our approach is to consider traces of interaction as knowledge sources that the designer can exploit in the design process. The principle technique of our proposal is to observe the quantitative and qualitative actions of actors on the learning platform and to represent them in modelled traces, to transform these traces in order to extract high level information on the actors activities, and finally, to propose visualisation tools of this information. We have applied our work in virtual campus VCIEL, where data for this study were obtained via participation of 2 designers, 13 tutors and 68 students from four classes that have been trained since 2006.