The Interoperability of Learning Object Repositories and Services: Standards, Implementations and Lessons Learned

摘要

Interoperability is one of the main issues in creating a networked system of repositories. The eduSource project in its holistic approach to building a network of learning object repositories in Canada is implementing an open network for learning services. Its openness is supported by a communication protocol called the eduSource Communications Layer (ECL) which closely implements the IMS Digital Repository Interoperability (DRI) specification and architecture. The ECL in conjunction with connection middleware enables any service providers to join the network. EduSource is open to external initiatives as it explicitly supports an extensible bridging mechanism between eduSource and other major initiatives. This paper discusses interoperability in general and then focuses on the design of ECL as an implementation of IMS DRI with supporting infrastructure and middleware. The eduSource implementation is in the mature state of its development as being deployed in different settings with different partners. Two applications used in evaluating our approach are described: a gateway for connecting between eduSource and the NSDL initiative, and a federated search connecting eduSource, EdNA and SMETE.