ISSN : 1796-217X
Volume : 2    Issue : 5    Date : November 2007

Description and Composition of E-Learning Services
Oussama Kassem Zein and Yvon Kermarrec
Page(s): 74-83
Full Text:
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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.

Index Terms
service description, service discovery, service composition, facilitator.