OAI-PMH at Yale Report on the DLF OAI Training Session November 10, 2005 Charlottesville, VA

Overview Review of the protocol OAI best practices Potential Yale applications Next steps for the Metadata Committee

OAI-PMH v.2.0 OAI-PMH v.2.0 Basic Concepts Data provider: administers systems that expose metadata Service provider: uses metadata to build value-added services Harvester: a client application that issues OAI-PMH requests Repository: a network accessible server that can process OAI-PMH requests

OAI-PMH v.2.0 OAI-PMH v.2.0 Basic Concepts Resource: the physical or digital object that metadata is "about" Item: a constituent of a repository from which metadata about a resource can be disseminated Record: metadata in a specific format Identifier: a unique identifier that unambiguously identifies an item in a repository; must conform to URI syntax

OAI-PMH v.2.0 OAI-PMH v.2.0 Harvesting Deleted records Sets Datestamps –ISO 8601ISO 8601 –UTC Selective harvesting

OAI-PMH v.2.0 OAI-PMH v.2.0 Protocol Features: HTTP Request –GET baseURL?key=value&….&key=value –POST baseURL Content-Type: application/x-www-form-urlencoded Content-Length: number of characters key=value&…&key=value Response –XML document in message body or error code

OAI-PMH v.2.0 OAI-PMH v.2.0 Protocol Features: XML Response XML declaration OAI-PMH root element with these attributes: –Default namespace declaration xmlns=“ –Schema instance declaration xmlns:xsi=“ –Schema location xsi:schemaLocation=“

OAI-PMH v.2.0 OAI-PMH v.2.0 Protocol Features: XML Response responseDate element –YYYY-MM-DDThh:mm:ssZ request element baseURL response element –It has the same name as the verb used in the request.

OAI-PMH v.2.0 OAI-PMH v.2.0 Protocol Features Multiple metadata formats –metadataPrefix Flow control –resumptionToken

OAI-PMH v.2.0 OAI-PMH v.2.0 Requests & Responses GetRecord Identify ListIdentifiers ListMetadataFormats ListRecords ListSets

Current Work: Resource Harvesting within the OAI-PMH FrameworkResource Harvesting within the OAI-PMH Framework Datestamps –Updated record vs. updated resource Locating the resource –Multiple URLs: splash page, resource, etc. –Multiple elements used inconsistently: dc.identifier, dc.format, dc.relation

Current Work: Resource Harvesting within the OAI-PMH FrameworkResource Harvesting within the OAI-PMH Framework Complex object formats –FOXMLFOXML –METSMETS –MPEG-21 DIDMPEG-21 DID –SCORMSCORM Other implementations –mod_oaimod_oai

OAI Best Practices OAI Best Practices DLF OAI Implementers Workshop Handouts from the session 1.Project Abstract 2.The Case for OAI 3.OAI “Cheat Sheet”: A Taxonomy of Rapid OAI Deployment Strategies 4.Summary of OAI Metadata Best Practices 5.Summary of the DLF Aquifer MODS Profile 6.OAI Tools 7.OAI Implementation: Administrative Planning

OAI Best Practices OAI Best Practices Implementation Decisions Collections –Develop criteria. Prioritize according to ease of implementation, associated risk, logical dependencies among items, etc. Metadata formats –Decide which formats to support. Technical infrastructure –E.g., use a gateway that provides a base URL for multiple individual collections.

OAI Best Practices OAI Best Practices Deployment Options Emory’s Metadata Migrator Static repositories UIUC’s OAI FileMakerPro Gateway Fedora Luna Insight

OAI Best Practices for Data Providers Identifiers –Should be persistent & unique. –Should not be reused. –Specification and XML SchemaSpecification and XML Schema Datestamps –Use UTC. –Support seconds granularity, if possible. Deleted records –Provide persistent support, if possible.

OAI Best Practices for Data Providers Resumption tokens –For repositories > 2 MB Sets –Service providers harvest by set. –How should sets be organized? About containers –RightsRights –Provenance (for 3 rd party aggregators)Provenance

Implementation Guidelines Includes: Guidelines for Repository Implementers Guidelines for Harvester Implementers

OAI Validation Reap: OAI command line harvestingReap Repository explorer: for data providers & service providers to test harvesting & searchingRepository explorer W3C validator for XML schema Utf8conditioner: for character encoding problemsUtf8conditioner See OAI Tools handout for more info.

OAI Best Practices for Shareable Metadata The four C’s of shareable metadata Consistency Coherence Context Conformance

OAI Best Practices for Shareable Metadata Metadata in a shared environment –Context & coherence –Don’t assume a local user. Granularity of description –Appropriate for access to the resource –Don’t expose records for subordinate items. Use of multiple metadata formats –Need to be expressed as XML schema –Stepped crosswalking to simpler formats.

OAI Best Practices for Shareable Metadata Relating versions of a resource –One-to-One Principle –Multiple strategies/compromises Document metadata creation practices –In OAI responses –In external documentation Communication with service providers

Potential Applications at Yale Implementation Goals Improve user experience –Federated search Improve management of resources –Finding aids Collaborate with institutional partners – AMEEL Develop digital library infrastructure –At Yale and beyond

Potential Applications at Yale Resources & Roles Resources –Commitment of stakeholders –Analysis of deployment options –Server infrastructure –Staff hours Roles –OAI-PMH Implementation Manager –Programmers & technical staff –Metadata specialists –Digital collection curators

Potential Applications at Yale Sharing Metadata 3 rd Party Aggregators –OAIsterOAIster –DLF PortalDLF Portal –MODS PortalMODS Portal Registries –Registered OAI repositoriesRegistered OAI repositories –Institutional Archives RegistryInstitutional Archives Registry –OAI Registry at UIUCOAI Registry at UIUC

Next Steps for the Metadata Committee Centralized implementation at Yale? If yes, –Relate to other digital library initiatives. –Create buy-in. Service provider needs –Consult with IAC committees. Data provider needs –Consult with digital collection curators.

Next Steps for the Metadata Committee Metadata recommendations –Recommend multiple formats –Decide upon a common format YES? MODS? Stepped crosswalking from other formats –Content & encoding guidelines –Metadata creation tools –Staffing