New development in OAI (OAI-PMH2)

The Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) is an evolving protocol and philosophy regarding interoperability for digital libraries (DLs). Previously, "distributed searching" models were popular for DL interoperability. However, experience has shown distributed searching systems across large numbers of DLs to be difficult to maintain in an Internet environment. The OAI is a move away from distributed searching, focusing on the arguably simpler model of "metadata harvesting". Perhaps the strongest and distinguishing feature of OAI is its simplicity: by being "smaller" than previous interoperability projects , it actually allows for more powerful and adaptable configurations and deployments. Key concepts in OAI include the separation of responsibilities of "service provider" and "data provider" and the use of community-specific metadata sets (with Dublin Core as a lingua franca). Key to understanding the philosophy of the OAI is understanding the separation of responsibilities of "service provider" (SP) and "data provider" (DP). In practice, a SP and a DP can reside in the same entity, but it is important to understand the distinction. A DP is a repository (or "archive") - simply a collection of metadata records (which may or may not point to corresponding full-text documents). A SP provides value added services (e.g., searching, browsing) on the metadata extracted from one or more DPs. SPs are free to define their own services, presentation and interfaces tailored to the user base. These services could be complimentary or competitive. The OAI-PMH consists of six verbs, 3 of which reveal the characteristics of the repository (ListMetadataFormats, ListSets, and Identify) and 3 verbs for extracting metadata from the repository (GetRecord, ListRecords, ListIdentifiers). OAI-PMH 2.0 is going to be realised in June of 2002, after 18 months of testing version 1.1. Although OAI-PMH 2.0 is not backwards compatible with 1.1, 2.0 represents only an evolutionary progression of the OAI-PMH. Some optional features for richer harvester - repository negotiation have been added, ambiguities removed, and extensibility hooks added for desirable features that lie outside of the scope of the protocol (e.g., machine readable rights management information). OAI-PMH projects and services are being announced frequently; check the Open Archives Initiative home page (www.openarchives.org) for the latest news. The OAI is entering the exciting phase where the focus is no longer just on the protocol, but more rightfully on the various services that use the OAI-PMH in novel and compelling ways as well as the community building that the OAI-PMH facilitates