The interoperability of learning object repositories and services: standards, implementations and lessons learned

Abstract

Interoperability is one of the main issues in creating a networked system of repositories. The eduSource project in its holisticapproach to building a network of learning object repositories in Canada is implementing an open network for learning services. Itsopenness is supported by a communication protocol called theeduSource Communications Layer (ECL) which closely implements the IMS Digital Repository Interoperability (DRI)specification and architecture. The ECL in conjunction withconnection middleware enables any service providers to join thenetwork. EduSource is open to external initiatives as it explicitlysupports 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 animplementation of IMS DRI with supporting infrastructure andmiddleware. The eduSource implementation is in the mature stateof its development as being deployed in different settings withdifferent partners. Two applications used in evaluating ourapproach are described: a gateway for connecting betweeneduSource and the NSDL initiative, and a federated searchconnecting eduSource, EdNA and SMETE.