The Open Archives Initiative Marshall Breeding Director for Innovative Technologies and Research Vanderbilt University Redefining Libraries: Web 2.0 and other Challenges May 2007 Xiamen, China

From Standards for Repository Interoperability Standards for Repository Interoperability The Open Archives Initiative develops and promotes interoperability standards that aim to facilitate the efficient dissemination of content. OAI has its roots in the open access and institutional repository movements. Continued support of this work remains a cornerstone of the Open Archives program. Over time, however, the work of OAI has expanded to promote broad access to digital resources for eScholarship, eLearning, and eScience. The Open Archives Initiative develops and promotes interoperability standards that aim to facilitate the efficient dissemination of content. OAI has its roots in the open access and institutional repository movements. Continued support of this work remains a cornerstone of the Open Archives program. Over time, however, the work of OAI has expanded to promote broad access to digital resources for eScholarship, eLearning, and eScience.

Model for federated search Harvest metadata from multiple repositories Harvest metadata from multiple repositories Index metadata on a central service Index metadata on a central service Offer a search interface on the central service Offer a search interface on the central service Deliver access to digital objects on the original repositories Deliver access to digital objects on the original repositories

Organization / Structure Data Providers Data Providers –Contribute metadata and content –Run a module that responds to requests for metadata Service Providers Service Providers –Harvest metadata from one or more repositories –Operate services that request metadata from data providers

Not MetaSearch Avoids pitfalls of “distributed-query” approach to federated search Avoids pitfalls of “distributed-query” approach to federated search Centralized, consolidated indexes allow for fast searching, sorting, ranking Centralized, consolidated indexes allow for fast searching, sorting, ranking Not dependent on persistent connections with multiple repositories Not dependent on persistent connections with multiple repositories

Open Archives Initiative Initiated in the pre-print servers for scholarly articles and research papers Initiated in the pre-print servers for scholarly articles and research papers Need to provide federated search model rather than having each researcher search each repository separately Need to provide federated search model rather than having each researcher search each repository separately Value-added services Value-added services Santa Fe convention – Oct 1999 Santa Fe convention – Oct 1999 Need to develop a protocol to create interoperability among many different types of repositories, each with different types of documents and metadata Need to develop a protocol to create interoperability among many different types of repositories, each with different types of documents and metadata

OAI-PMH Open Archives Initiative Protocol for Metadata Harvesting Open Archives Initiative Protocol for Metadata Harvesting XML protocol for harvesting metadata XML protocol for harvesting metadata Uses unqualified Dublin Core as default Uses unqualified Dublin Core as default Each community can specify its own metadata formats and profiles Each community can specify its own metadata formats and profiles A simple protocol designed to have a low threshold of difficulty for implementation A simple protocol designed to have a low threshold of difficulty for implementation

OAI-PMH Requests / Response Identify Identify ListIdentifiers ListIdentifiers ListMetadataFormats ListMetadataFormats ListRecords ListRecords ListSets ListSets GetRecord GetRecord

A standard protocol Initial 1.1 version in July 2001 Initial 1.1 version in July 2001 Version 2.0 completed in June 2002 Version 2.0 completed in June 2002

Operational considerations Initial contact of an OAI harvester to a repository may involve a massive transfer of records Initial contact of an OAI harvester to a repository may involve a massive transfer of records Resumption token provides a mechanism for the repository to interrupt the transfer Resumption token provides a mechanism for the repository to interrupt the transfer –Harvestor may come back at a later time to resume the transfer Subsequent requests involve only added and changed records Subsequent requests involve only added and changed records

OAI in action Widely implemented Widely implemented Part of the standard infrastructure for pre- print servers, institutional repositories, etc. Part of the standard infrastructure for pre- print servers, institutional repositories, etc. –D-Space –Fedora Pragmatic approach for any application needing to transfer records between systems Pragmatic approach for any application needing to transfer records between systems Some service providers use additional protocols Some service providers use additional protocols

Examples Networked Digital Library of Theses and Dissertations Networked Digital Library of Theses and Dissertations The American South The American South –AmericanSouth.org

Implementations Tools available in many different programming languages and environments Tools available in many different programming languages and environments Built-in to many digital library applications Built-in to many digital library applications

For detailed information: Understanding the Protocol for Metadata Harvesting of the Open Archives Initiative (Marshall Breeding, Computers in Libraries, Sept 2002) Understanding the Protocol for Metadata Harvesting of the Open Archives Initiative (Marshall Breeding, Computers in Libraries, Sept 2002) displaytext.pl?RC= displaytext.pl?RC= displaytext.pl?RC= displaytext.pl?RC=9944