In a pedagogical re-engineering process, it is important to be able to compare the effective system usage with prescribed scenario (which can be formalized with an Educational Modeling Language). We think that computer tracks resulting from e- learning system usage make up pedagogical objects by themselves and thus they can be modeled with the help of an EML. In this paper, we will show that such an approach is interesting. We will more particularly focus on how to represent computer tracks with a specific EML (IMS Learning Design) and to highlight some cases in which this comparison of two LD scenarios (the prescribed one and the synthesized one) brings useful information to understand the effective progress of the learning session.