the dublin core metadata initiative, the resource description framework, and purls november 6, 2000...

The Dublin Core Metadata Initiative,The Resource Description Framework,

and PURLs

November 6, 2000

Stuart WeibelStuart WeibelSenior Research ScientistSenior Research ScientistOCLC Office of ResearchOCLC Office of Research

Director, Dublin Core Metadata InitiativeDirector, Dublin Core Metadata InitiativeCopyright 2000 - All Rights Reserved

FAO Workshop on Metadata Standardsfor Electronic Publishing in Agriculture

Brussels, Belgium

2

Metadata for Resource Description and Discovery

A resource description community is characterized by common semantic, structural, and syntactic conventions for exchange of resource description

information

Libraries

MARC AACR2

3

The Internet Commons embraces many Resource Description Communities

ScientificData

HomePages Geo

InternetCommons

Library

Museums

Commerce

Education

4

OK, OK….(but never mind)

COMMERCE

5

DCMI:The Dublin Core Metadata Initiative

DCMI is an open consensus building initiative International scope 2 major ‘products’ and supporting documents

(so far) A process A community A culture A forum

6

Mission of the DCMI

The mission of the Dublin Core Metadata Initiative (DCMI) is to make it easier to find resources using the Internet through the following activities: Developing metadata standards for resource

discovery across domains Defining frameworks for the interoperation of

metadata sets Facilitating the development of community- or

domain-specific metadata sets that work within these frameworks

7

Scope of Activities

Standards Development meetings and workshops to

support development of standards and best practice

Communications Website, working drafts,

documentation, recommendations, mailing lists...

Liaisons Promote interoperability

through liaison activities with other initiatives

Tools and Services promote availability of tools

to support creation, management, and use of DC metadata

Metadata Registry:infrastructure for managing vocabularies in multiple languages

Research Advance the infrastructure

and frameworks to support metadata interoperability

8

Liaisons

IEEE-LOM, IMS Education Resources

GILS MPEG W3C

Open Archives Initiative

Electronic Theses and Dissertations

RSS XML.COM

Development of liaisons with other metadata activities will improve prospects for interoperability

9

The Dublin CoreMetadata Element Set

Title Author/Creator Subject /Keywords Description Publisher Other Contributor Date

Resource Type Format Resource Identifier Source Language Relation Coverage Rights Management

10

Dublin Core Workshop Series

Chicago WWW Conference Oct, 1994 OCLC/NCSA Metadata Workshop Mar, 1995 OCLC/UKOLN Warwick Workshop, UK Apr, 1996 CNI/OCLC Image Metadata Workshop Sep, 1996 DC-4, Canberra, Australia Mar, 1997 DC-5, Helsinki, Finland Oct, 1997 DC-6, Washington, DC, USA Nov, 1998 DC-7, Frankfurt, Germany Oct, 1999 DC-8, Ottawa, Canada Oct, 2000

11

The Dublin Core Metadata Initiative

Dublin CoreWeb Site

http://purl.org.dchttp://dublincore.org

DC-General Dublin Core Mail Server

Working Groups

DCAdvisory Committee

Dublin CoreDirectorate

DC Executive Committee

Stakeholder Communities

12

Adoption by Major Communities

Australia, Denmark, Finland: public information discovery

Cultural heritage institutions

Libraries Educational resources Print and Preprint

archives NASA/JPL image

archives

Software repositories eBooks Financial and Insurance

industries Aerospace and

Automotive applications GIS applications Health Commerce: information

syndication (RSS)

13

DCMIOpen Source Software

Collaborative development promotes community commitment

Promote toolkits, utilities, and applications that support the creation, management, and exploitation of metadata

We hope many will contribute

14

DCMI Open Metadata Registry

EOR: Managing vocabularies defined by DCMI Languages Versioning Controlled vocabularies

Foundation for modular, incremental integration and evolution

Collaboration with European Schema project, ULIS in Tsukuba, Japan, ILRT (SchemaRama) in Bristol

http://rdf.dev.oclc.org/myrdf/services/EOpenRegistry

15

LC

NA

F

MA

RC

-Re l

a ter

Co

des

Juri

sdic

t io

n

DCMI Matrix of Semantics and Communities

Tit

le

Cre

a to

r

Pu

bli

s he

r

Co

ntr

i bu

tor

Dat

e

Rel

ati

on

So

urc

e

Iden

tif i

er

Lan

gu

ag

e

Su

bje

c t

Des

cri p

tio

n

Co

v era

ge

Fo

rma t

Typ

e

Rig

hts

DCMI

Au

die

nce

DC-Education

DC-Library

DC-Government

16

Alternative Representations of DC Metadata

Japanese

English

Portuguese

Danish

17

The Complete Matrix:A registry of metadata Semantics

18

Standardization

CEN Workshop Agreement formalized in January, 2000 Endorse Version 1.1 Dublin Core element set as

CWA 13874 Providing guidelines for industry to assist the

adoption of Dublin Core in Europe Establishing active participation and contributions

from relevant projects and activities, resulting in a web based "Observatory" on European work on metadata.

19

Launched: January 15, 1999

as cooperative OCLC research project Re-release: July 1, 2000

as integrated OCLC library service Key objectives:

Ongoing user input to shape features and priorities International scope, global use Minimize redundant effort by libraries Release system quickly, improve continuously Embrace key international standards

purl.oclc.org/corc

CORC:Cooperative Online Resource Catalog

20

CORC’s key features

Requires only Web-browser for access/use Incorporates key international standards:

Metadata: Dublin Core, AACR2/MARC Characters: Unicode, ALA Character Set

Automates the creation and maintenance of: Resource records (bibliographic records)

Including URL management (automation + cooperation) Authority records (established forms of names) Pathfinders (Webliographies)

Offers Web access to DDC Integrated with OCLC Cataloging & FirstSearch

21

NISO

NISO: Z39.85 Fast Track balloting concluded August 15;

Z39.85 has been approved, pending completion of administrative requirements

ISO Fast track process is a natural successor

22

RDFResource Description Framework

W3C’s RDF Resource Description Framework Resources

anything that can be identified

Description Framework Design of enabling technologies to support description of

these resources

23

RDF is ...

Data Model Model to support a web of named relationships connecting

uniquely identified things. XML representation Designed to impose structural constraint on syntax to support

consistent encoding, exchange and processing of metadata Schema

Enables resource description communities to a consistent means of declaring vocabularies

Enable reuse (museum, library, e-commerce…) Bootstraps Data Model

24

What you really need to know about RDF

It is XML based XML DTDs… extensibility is a problem RDF Schemas and XML Schemas are at least

partially in competition, and the dust has not settled

The market place will tell us…

25

RDF Schema

Designed to enable resource description communities the ability to define (and share) vocabularies

Support basic semantic integrity constraints Characteristics of classes or properties and/or constraints on

corresponding values

Support basic semantic relations “Illustrator” is a refinement of “Creator”

Designed to be extended

26

RDF Statements

…<rdf:Description rdf:about = “http://doc”> <bib:author rdf:resource = http://Stu /></rdf:Description>…

http://docbib:author

Statement

(http://doc, bib:author, http://Stu)

http://Stu

27

RDF Example 1

“Stuart Weibel”

URI:R“FAO Presentation”

title

creatordc:

dc:

<?XML version=‘1.0’?><rdf:RDF xmlns:rdf=“http://www.w3.org/TR/REC-rdf-syntax#”

xmlns:dc=“http://purl.org/dc/elements/1.1/”> <rdf:Description rdf:about = “URI:R”> <dc:title> FAO Presentation </dc:title> <dc:creator> Stuart Weibel </dc:creator> </rdf:Description></rdf:RDF>

28

RDF Example 2

URI:R“FAO Presentation”

title

creatordc:

dc:

<?XML version=‘1.0’?><rdf:RDF xmlns:rdf=“http://www.w3.org/TR/REC-rdf-syntax#”

xmlns:dc=“http://purl.org/dc/elements/1.1/”> <rdf:Description rdf:about = “URI:R”> <dc:title> FAO Presentation </dc:title> <dc:creator rdf:resource = “URI:Stu”/> </rdf:Description></rdf:RDF>

URI:Stu

29

“Eric Miller”“Eric Miller”

RDF Data Model Example 3

URI:R“FAO Presentation”

title

creatordc:

dc:

URI:ERICURI:Stu

“stu@oclc.org”“Stuart Weibel”

“OCLC”

bib:emailbib:affbib:name

URI:OCLC

URI:Personrdf:type

30

PURLs

Persistent URLs

31

Persistence

Persistence of Naming Persistence of content is a different problem -- digital

archiving -- and its REALLY hard

Persistent names are NOT a matter of technology Commitment of organizations charged with

responsibility for managing content and access

Technology is only a part of the solution (and it’s the easy part)

32

PURLPersistent URLs

In Computer Science: no problem that cannot be solved with an additional level of indirection!

PURLs: Redirect a symbolic name to a network location

No New Technology! Simple public domain db URLs simple tools to manage the PURLs

It’s free (http://purl.org)

33

Persistent Naming of Resources

Naming is easy: even the State of Ohio can do it Naming is hard: the IETF has failed to do it for

years (URNs) Naming is contentious: There are many naming

schemes, tailored for different purposes But it is going to happen… it is necessary

34

OCLC’s Naming Service

Under development (Albert Simmonds Basic Model:

Give me a name Ask for a service

Provide an architecture for the OPEN definition of services that can be applied to known resources integrate sectors… for profit, not for profit,

governmental, supra-governmental….

35

Examples of Services on Names

Given a named resource… let me buy it let me borrow it give me the citation show me the metadata show me the title page show me a review let me write a review tell me who owns it ….

36

Impediments

Legacy systems ISBN, ISSN, Name Authorities, DUNs Numbers, on

and on and on….

Architectures Probably best to avoid the Unitary Theory of Naming

Business models are shaky Who pays for maintaining persistence of naming and

content? Libraries? Publishers? Users? Governments?

37

Additional Information

Dublin Core Home page http://purl.org/dc

W3C RDF Home Page http://www.w3.org/RDF

EOR Demo http://wip.dublincore.org