OAI & OAI-PMH Albulena Bruncaj LIS 882 Metadata for Internet Resources
What is OAI? The Open Archives Initiative OAI is a framework that deals with interoperability standards for digital resources Traces its roots to the open access and institutional repository movements (e-prints) It is “explicitly in transition” Their goal is to define a “low-barrier” framework for cross-repository interoperability
OAI-PMH – A Brief History The Open Archives Initiative Protocol for Metadata Harvesting The framework provides a technical mechanism for harvesting metadata from repositories Santa Fe meeting (1999) Cross-searching multiple archives based on Z39.50 or harvesting metadata into one or more "central" services in a bulk move of data? OAI-PMH 1.0/1.1 followed by OAI-PMH 2.0
Repositories As defined by OAI-PMH, a repository is a network-accessible server that exposes metadata to harvesters Three entities related to this accessible metadata: Resource Item Record
Records header (mandatory) identifier Datestamp (YYYY-MM-DD) setSpec elements status attribute for deleted item metadata (mandatory) XML encoded metadata with root tag, namespaces repositories must support Dublin Core, may support other formats about (optional) rights statements provenance statements
setSpec Sets are optional Enable a logical partitioning of repositories, but they are not necessarily hierarchical Not necessarily exhaustive of content Helps facilitate selective harvesting, however Publication type Document type Content sets
The Fun Part! OAIster http://oaister.worldcat.org/
Requests & Reponses Both use HTTP Request types (also called the “verbs”) Identify ListMetadataFormats ListSets ListIdentifiers ListRecords GetRecord
DSpace OAI-compliant Free, out-of-the-box software that enables access to digital content Examples: http://timea.rice.edu/browse.jsp http://modiya.nyu.edu/
CONTENTdm CONTENTdm is a software used for the management of digital collections Widely used Metadata in CONTENTdm can be harvested through OAI-PMH Allows collection curators to extend basic Dublin Core schema to include locally defined fields Example: http://content.lib.washington.edu/
CONTENTdm – Tension At minimum, simple Dublin Core is required CONTENTdm offers an easy way to make their metadata (and thus, digital collections) available while simultaneously providing curators with the means to create local, non-standardized metadata
Issues with OAI-PMH Libraries face the challenge of creating metadata that both meets the requirements of local practices in granularity (e.g., putting certain content in fields not harvestable by others) and wanting to share their digital collections widely Is there any solution? Or are we all left to figure out our library’s balance on our own?
Bibliography An overview of OAI OAI-PMH. 12 Nov. 2010. Retrieved from http://www.slideworld.org/viewslides.aspx/An-Overview-of-OAI--OAI-PMH-ppt-2369922 Han, M., Cho, C., Cole, T.W., and Jackson, A.S. “Metadata for special collections in CONTENTdm: How to improve interoperability of unique fields through OAI-PMH.” Journal of library metadata, 9(3/4), 213-238. OAI. 12 Nov. 2010. Retrieved from http://www.openarchives.org/ "OAI-PMH online tutorial." Open Archives Forum. 12 Nov. 2010. Retrieved from http://www.oaforum.org/tutorial/ Zeng, M.L., and Qin, J. (2008). "Metadata repositories." In Metadata (224-232). New York: Neal-Schuman.