In this article, we present, through a case study, the phases which structures the learning scenarios within a MOOC: the planned scenario, the effective scenario and the real scenario. This structuration shows different choices of the design team from the pedagogical objectives, which have been decided at the beginning of the project, which have been adapted and instrumentalised and the consequences of theses choices on the evolution of the scenario. This study raises questions about methodology and techno-pedagogical adaptations which are necessary nowadays to respond to the initial objectives.