Learn more about ERRoL

OCLC's ERRoL service provides a convenient human interface to explore, reference, and manipulate OAI repositories from your web browser or other web client. ERRoL is basically an OAI identifier resolution service.  It works with any repository listed in the OAI Registry at the University of Illinois at Urbana-Champaign, providing free value-added services to OAI repositories with no extra effort required on the part of the data providers. Examples of these services include URL access to OAI metadata and the content described, HTML displays, OAI version transformations, and RSS feeds. The resolution of these URLs involves invoking OAI requests to the repository behind the scenes and then transforming and manipulating the responses into something new.

"ERRoL? Why's it called that?"

The important concepts embedded in this service are Extensibility (of a core URL), Repositories, and Resource Locators. The "o" just makes it easier to pronounce. ERRoL stands for Extensible Repository Resource Locators.

The ERRoL service brings together a number of important technologies:

OAI repositories and the need to build services for them to make the data useful. We've created modular services so that others don't have to build those services, making the data interactively displayable, URL accessible, and manipulatable.

Uniform Resource Locators. We've created a URL pattern incorporating OAI identifiers that can be extended so they resolve to content, metadata and services related to those identifiers.  ERRoLs are elegant and simple; ERRoLs are available to any registered OAI repository and the user interface and resolution services can be customized and extended beyond what's supplied by OCLC's ERRoL service.

Persistence. Very important concept. ERRoLs can effectively be used in place of PURLs and Handles within the OAI domain.

OpenURL Registry. Much of this functionality was introduced in the OpenURL registry service that OCLC Research developed.  With ERRoLs, we've decoupled the OAI "extensions" developed there and made them available for any OAI repository that has a unique "registered" repositoryIdentifier.