Learning design: models for computers, for engineers or for teachers?

In this paper, we focus our attention on the authoring approach applied on learning scenario's management. We present the challenges raised by this issue by proposing a precise definition of the concept of learning scenario and its lifecycle. Then, we present current works aiming to capture and analyze the practitioners' needs and usages and to co-build models and tools matching with their specific context and environment. To conclude, we wonder about the possibility of considering a federative meta-model whereas at least three different targets must be considered: models for computation, models for design specialists and models for practitioners such as teachers