SEMANTIC WEB AND PEER-TO-PEER TECHNOLOGIES FOR DISTRIBUTED LEARNING REPOSITORIES

摘要

Metadata for the World Wide Web is important, but metadata for Peer-to-Peer (P2P) networks is absolutely crucial. In this paper we discuss the open source project Edutella and related projects, which combine semantic web and peer-to-peer technologies in order to make distributed learning repositories possible and useful. We describe the main services of the Edutella network infrastructure and its architecture based on the exchange of RDF metadata, starting with the query service as one of the core services of Edutella. We discuss the Edutella Common Data Model (ECDM) as basis for the Edutella query exchange language (RDF-QEL-i) implementing distributed queries over the Edutella network, and discuss as one example an O-Telos-Peer with native Datalog query and inference capabilities. We then sketch a new P2P routing topology which minimizes broadcast traffic and distance between the peers in such a network, as well as a modification language needed for supporting distributed update and annotation. A short section discusses the changing role of adaptation in these distributed repositories (as open corpus hypermedia instead of the closed ones investigated in most research projects so far). Finally, we discuss an application of the Edutella network for digital libraries (OAI-P2P) and the use of Edutella in the ELENA project which aims to create smart spaces for learning.