OAI from 50,000 Feet OAI develops and promotes interoperability solutions that aim to facilitate the efficient dissemination of content. Begun in 1999.

OAI from 50,000 Feet

• OAI develops and promotes interoperability solutions that aim to facilitate the efficient dissemination of content.”

• Begun in 1999 to encourage the development of e-print solutions

• Archive = Repository

• “Open” means facilitating the availability of content from many different providers; does not mean “free” or “unlimited”

OAI from 50,000 Feet

• OAI’s technological framework and standards are independent of content offered and the economic mechanisms surrounding that content

• Technical framework provides low barrier for interoperability

• Data providers adopt the OAI technical framework as a means of exposing metadata

• Service providers harvest metadata from data providers using the OAI protocol and use the metadata fro value-added services

• OAI metadata uses unqualified Dublin Core, and all fields are optional

OAI and UT

• Open Archives Initiative (OAI) - http://www.openarchives.org/

– Joint effort between DLF and Mellon Foundation

– Documents, tools, community listservs, latest OAI news and updates.

– Data Providers and Service Providers – Harvesting Protocol

– Data = Server (has data and waits for someone to come get it)

– Service = Client (sends a request to data provider) – Old Dominion

• Mellon grants of approx. $1.5M for service providers

• University of Tennessee– UT Library was a founding member of the (DLF) - http://www.diglib.org

– UT is a Data Provider for OAI.

– UT currently uses OAI with TEI, EAD, JPEG, PDF, RM, and other formats. OAI Records on UTK Sunsite. Digital Objects on other servers.

OAI Records - General

• Each OAI Record and the repository must be compliant with the protocol; however,– OAI Protocol not concerned with policies of individual

archives

– No implications for physical storage, cost of data, or access control to server.

– No specifications for metadata and data formats

OAI Records - Continued

• A record is a piece of XML that stores metadata.– XML schema specifies the structure. Very precise.

• Each record must be uniquely addressable.• Each metadata entity must be persistent

– Metadata must be persistent.

– Object can change or cease to exist.

– If metadata is persistent the record can always be found but you don’t have to keep the object forever.

OAI Records - Continued

• Each record contains three parts:1. Mandatory – Header

a. Contains unique identifier (oai:utk:vid/vid0001)

b. Data stamp (update as record is changed)

2. General and Options – Metadata

a. Mandatory - oai_dc (unqualified dublin core)

b. Optional - EAD, MARC, RDF, CIMI, TEI, etc.

3. Optional – About

– a. About the metadata (metadata is about the data)

Unqualified Dublin Core and OAI

• 15 Dublin Core Elements– All are optional; All are repeatable

• Sets – Optional– Nothing to do with OAI protocol– Everything to do with the archive

Unqualified Dublin Core - OAI_DC

OAI Record for Video

OAI Repository Explorer

• Enforces interoperability by testing quality of metadata

• Tests interfaces• Simulates use of an archive (repository) by a

typical service provider• Allows browsing of an archives contents using

only the OAI protocol.• Checks syntax and encoding of data.

OAI Repository Explorer 1.1

SOAP - Simple Object Access Protocol

Version: 1.1

W3C Note 08 May 2000

“Simple and lightweight mechanism for exchanging structured and typed information between peers in a decentralized, distributed environment using XML.”

3 Parts: SOAP Envelope, SOAP encolding rules and SOAP RPC (remote procedure calls and responses).

http://www.w3.org/TR/SOAP/#_Toc478383486

OPTIONS FOR SHARING METADATA

SOAP

“fundamentally one-way transmissions from a sender to a receiver but SOAP messages may be combined to implement patterns such as request/response.”

Headers can contain information or applications to be used by intermediate destinations. The body contains the information for the ultimate destination.

One way initiation.

Not intended for bulk data mining

Z39.50 Information Retrieval Application Service Definition and Protocol Specification

Granular - Can search by any query attribute, including format (problems--multiple formats, inconsistent use for moving images)

Also a profile for holdings, to identify multiple copies of an object.

Would need extension for bulk mining.

http://www.loc.gov/z3950/agency

DESIGNING METADATA TO SUPPORT OAI

DESIGNING METADATA TO SUPPORT OAI

<identifier>http://www.anyarchive.org/delrec.html </identifier>

<title> This title is no longer available </title>

<date.deleted> 2001-18-15</date.deleted>

<description> Please contact the archive reference department for assistance in locating an alternative resource: [email protected]</description>

DESIGNING METADATA TO SUPPORT OAI

Response record returned for deleted metadata record