Digital libraries research IG

Cataloging and metadata IG

Digital libraries research IG

Cataloging and metadata IG

Web services and metadata switch February 2003

Web services and metadata switch February 2003

ContextContext

• Libraries• Libraries are creating more metadata for more types of

material. • They are using different metadata schema and content

standards • They are using different systems and workflows.

• For OCLC• Much of the value of what we offer is embedded in

integrated systems which meet a central need, but which may not support the changing working patterns of all our potential users.

• We need to explore how to break down services into components which our users can build back up within their environments and workflows

• We also need to figure out how to make our existing investment in structured metadata work more for us by mining, developing, and exposing relationships across documents and other resources.

Response: metadata switchResponse: metadata switch

• A set of projects which explore services which• … add value to metadata

– through transformation, enrichment, recombination, …

• .. and are delivered as modular, web-based machine-to-machine applications (web services).

• Some test cases– ContentDM– ‘portal service’– UK e-prints

Some putative examples of servicesSome putative examples of services

• Schema transformation– give me a MARC record: I will give you back a DC one

• Terminology service– Give me a Dewey number: I will tell you if it is valid– Give me an ISBN: I will give you back Dewey numbers associated with

the book– Give me a Dewey number: I will send you back corresponding Eric

headings– Give me a document: I will suggest some FAST headings

• Name service– Give me name: I will give you back matching names from an authority file

• Work service– Give me an ISBN: I will give you back ISBNs for books in the same ‘work’

• Format service– Give me an object in one format: I will give you back one in another– Give me an object in one format: I will validate it

What are ‘web services’What are ‘web services’

• A way of exposing functionality as modular components

• “network accessible application components”• “interoperable building blocks for constructing

applications”• “self-describing applications that can be discovered and

accessed over the web by other applications”

• Technical definition– Web Services are a suite of protocols that define

how requests and responses between software applications should be encoded & transferred over the web

More on web servicesMore on web services

• Machine-to-machine communication• Run over standard Web protocols

– XML syntax, HTTP packaging

• Several approaches– REST

• Representational State Transfer• Simple: HTTP request; XML or HTML response• OpenURL; Open Archives Initiative; SRU

– SOAP• Simple Object Access Protocol• More complex: XML • SRW• WSDL, UDDI

Some objectivesSome objectives

• How will services work in more distributed environments?

• What metadata/knowledge organization services would be useful in these environments?

• How should they be delivered?• What role will OCLC play?• Who do we collaborate with?

To follow:To follow:

• Thom Hickey– Names– Works

• Diane Vizine-Goetz– Terminology

• Jean Godby– Schema transformation

• Discussion