What is the Open Archives Initiative (OAI) Protocol for Metadata Harvesting (PMH)?
(back to top) The Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) supports interoperability between disparate collections of metadata.It achieves interoperability through metadata harvesting rather than through distributed searches as in the Z39.50 protocol. In Z39.50, searches are requested simultaneously across multiple metadata providers. Each provider searches their own metadata and returns results to the search service, which aggregates results from all responding providers. In contrast, when OAI-PMH is used, the metadata itself is completely or selectively harvested from each metadata provider and aggregated in a central location. Searches are then performed within this central repository. The Open Archives Initiative is the organization responsible for the metadata harvesting protocol used in the IMLS DCC project. The OAI protocol is based on XML and HTTP. A service provider sends an HTTP request to a data provider using the protocol. The metadata provider—wh
