DS CWA 16385:2012

Interoperability of Registries

Scope

Typically, a federation of repositories consists of a number of participating Learning Object Repositories. The locations of those repositories and the description of the protocols they support for exposing their learning resources to the federation are maintained and managed at the federation level. This can either be managed:
• By tools such as harvesters or federated search engines that connect the repositories to the federation, or
• In a separate registry that manages this information for all the repositories on behalf of these tools.
These registries are generally not available outside of the individual federation in which they operate. The obvious problem is that this leads to a duplication of effort because repository descriptions must be entered in the registry of each federation where they are a member. As the result, there are difficulties to keep the information up-to-date across all the registry instances in all the federations. For example, if the Open Learn (OU-UK) repository changes the location of their OAI-PMH target, the location should be changed in the registries of ARIADNE, ASPECT, ICOPER, etc.
The present document gives guidance to enable the connection of learning object repositories, in order to further increase their impact in making relevant content available to teachers, trainers and (life-long) learners, by specifying how a network of registries can be set such that changes in the description of a repository only needs to be made once. This document does not build new specifications but rather profiles existing specifications.
Therefore, this CWA will focus on the following topics:
- Overview of the data model that can be used to describe collection registries (Clause 5),
- Specify protocols and APIs that can be used to provide access to these registries (Clause 6),
- A Collection Registry Specification (Clause 7),
- Registry reference implementations that can be used to validate the specifications (Clauses 8 and 9),
- Case studies (Clause 10).
The data model and APIs facilitate the use of registries by external tools that can manage, query or update the information that the registries contain. They make it possible to share registries between federations, thus enabling the automatic discovery of repositories and the automatic federation to new repositories into a federation.