Description and Composition of E-Learning Services

In this paper, we present our approach to describe and compose services for distant learning and research activities. For this purpose, we propose a metadata model for indexing services with three dimensions: a service can be viewed as a learning resource, as a resource that contribute and help researchers to perform their tasks in a community and as a service with a large scope. This model can be used by clients (learners/teachers or researchers) to query and discover services via for example a facilitator we have developed. We propose an approach for automatic composition of services which is based on facilitator. It relies on the semantic description of service behavior. We describe the latter with an automaton. This includes the description of the interface through the inputs/outputs and conditions (post and pre-conditions) that control the operations. We extend the functionalities of the facilitator to become a composition engine that enables services or resources to be composed automatically by comparing their inputs/outputs flows to help learners/researchers in their distant learning and research activities.