Metadata Vocabularies in Subject Gateways for Japanese Regional

Public Libraries

Shigeo SugimotoResearch Center for Knowledge CommunitiesGraduate School of Library, Information and

Media StudiesUniversity of Tsukuba

Some Japanese Governmental Activities, Metadata Vocabularies, and

a Model for Sharing Metadata Schemas

Shigeo SugimotoResearch Center for Knowledge CommunitiesGraduate School of Library, Information and

Media StudiesUniversity of Tsukuba

DC in Japanese Industrial Standard• Simple Dublin Core has been accepted as a

National Standard in March 2005 by JIS. JIS X 0836

• Translation of ISO 15836• Key issue for translation

– Choice of Japanese terms for Labels, which should be domain neutral

– Example: Subject element• 主題、件名　

– Straightforward translation of “subject” – Library oriented terms, possibility of confusion with the meaning

of Title

• キーワード（ keyword）– Domain Neural– chosen for JIS X 0836

Some Activities in Japan• Preservation

– Web Archiving: National Diet Library (NDL)– Governmental Resources: NDL and National

Archives of Japan• NDL

– National Deposit Library– Appointed as the central organization for national

Web archiving• Revision of Law for legal deposit

• National Archives of Japan– Archiving of government resources

• Born digital resources• Definition of “Governmental Resource”

– Central repository for government documents

Digital Okayama Dai-Hyakka (DODH)

• DODH– Regional portal by the Okayama Prefectural Library– Metadata creation by librarians and non-professional

s, e.g. school teachers, students, and volunteers.

• A Key Issue: Subject Classification– Choice of subject vocabularies– Small set of subject terms usable for the non-professi

onals designed in accordance with regional needs.

Basic Ideas in DODH• Basic Question:

Is comprehensive/conventional subject vocabulary really useful?

• Use domain specific vocabularies in addition to a comprehensive and widely used by libraries– Three vocabularies

• NDC (Nippon Decimal Classification)– Very widely used by Japanese libraries

• Kid’s Vocabulary– Designed for children and child resources

– Multiple labels in accordance with user ages

• Prefectural Resource Vocabulary – Developed by the government of Okayama prefecture for their r

esources

Basic Ideas in DODH• Maintenance of subject vocabularies

– Librarians’ major concern on domain specific vocabularies

• This is still an open question.

– Need software tools to maintain vocabularies• Metadata Schema Registry• Semantic Web technology

Some Issues on Subject Vocabularies

• Comprehensive and conventional subject vocabularies are not always useful for domain-specific resources.– Regional governments’ vocabularies for

classifying resources

• Comparison between the three subject vocabularies– Mappings between all pairs of these three

vocabularies show the characteristics of vocabularies and requirements for classifying resources from different perspectives.

Classification Vocabularies of Four Prefectural Governments in Japan

Ibaraki Kagawa Kanagawa Okayama

Number of Top Level terms 23 11 14 16

Max Depth 2 2 2 3

Total Number of Terms 115+ 82 88 280+

“+” means that terms to express names of regions or organizations

are excluded.

Okayama

Ibaraki

Kanagawa

Kagawa

Tokyo

NDC 000 100 200 300 400 500 600 700 800 900 total

#Kids

terms17 8 8 196 58 54 28 62 6 6 443

#NDC in KV

7 7 3 44 27 27 20 26 4 4 169

#Pref

terms15 2 12 171 30 56 44 17 1 1 349

#NDC in PV

4 2 5 34 11 18 25 15 1 1 116

Distribution of Terms in the NDC term space - Okayama’s Case -

NDC: 000=Generalities, 100=Philosophy, 200=History, 300=Social Sciences, 400=Natural Sciences, 500=Technology, 600=Industry, 700=The Arts, 800=Language, 900=Literature #NDC in KV/PV: the number of NDC terms in x00 used in the KV/PV mapping

Subject Vocabularies - Okayama’s Case -

NDC

PV KV

Social ScienceTechnology

Natural ScienceArtsIndustries

Comprehensive

Educational and Learning Resources

Resources for Government and Social Activities

General Resources

Discussions • Interoperability vs. Domain Specificity

– Reasonably small and domain-specific vocabulary is advantageous for domain-specific applications.

– Domain-specificity is, in general, disadvantageous for interoperability

• Maintainability of Vocabularies– Long-term maintenance of vocabularies is expensive.

• Reusability and customizability– Neighboring communities would need to share a

vocabulary in part.

• Need a good model to solve these issues

A Model for Reusing Metadata Schemas

termA: Mandatory

termC: Optional

Repeatable

termX: Mandatory

Repeatable

termZ: Mandatory

if applicable

termX termY termZ

Metadata Vocabulary 2(Metadata Element Set)

Metadata Vocabulary 1(Metadata Element Set)

termA termB termC

A structural view of application profile

A Model for Reusing Metadata Schemas

termA: Mandatory

termC: Optional

Repeatable

termX: Mandatory

Repeatable

termZ: Mandatory

if applicable

Application Profile: Terms used in an application and structural constraints

termX termY termZ

Metadata Vocabulary 2(Metadata Element Set)

Metadata Vocabulary 1(Metadata Element Set)

termA termB termC

<rdf:Description about=”foo”> <mv1:A>an example.</mv1:A> <mv2:X>bar</mv2:X> ...

<meta name=”mv1:A” content=”an example”><meta name=”mv2:X” content=”bar”>

...

Description in a syntax defined in an application

Application Profile

Abstract Syntax and Concrete Syntax

A Model for Reusing Metadata Schemas

Layered Model of Metadata Schema

Layer 1Semantics

Layer 2Abstract Syntax

Layer 3Concrete Syntax

DCMES (Elements and

Qualifiers)IEEE-LOM ULIS element

extension

DCMI Library Application

Profile

Open Archives Initiative Schema

IPL Asia Schema

ULIS Core Schema

XML implementation

in an XML Schema

An Oracle implementation

RDF implementation

A Layered Modelsplit semantics and syntax into layers

A Model for Reusing Metadata Schemas

Layer 1

Layer 2

Layer 3

DCMI Registry

DCMES Terms

(Elements and Qualifiers)

ULIS element extension

ULIS-DL Subject

Vocabulary

Tsukuba Registry

Application Profile A Application Profile B

Layered Model and Metadata Schema Registry

A Model for Reusing Metadata Schemas

Layer 1

Layer 2

Layer 3

DCMI Registry

DCMES Terms

(Elements and Qualifiers)

ULIS element extension

ULIS-DL Subject

Vocabulary

Tsukuba Registry

XML Schema for A XML Schema for B

Layered Model and Metadata Schema Registry

A Model for Reusing Metadata Schemas

Layer 1

Layer 2

Layer 3

DCMI Registry

1. Use registries to share, reuse, customize and maintain vocabularies

2. Develop software tools to support these functions.

Tsukuba Registry

Layered Model and Metadata Schema Registry

Discussions • Need good model and software tools

– DCAM provides the basic architecture of metadata elements and metadata descriptions

– The layered model presented is designed in order to enhance reusability/customizability of metadata schemas by splitting semantic and syntactic features of metadata schemas.

• Metadata Schema Registry as a key component to share metadata schemas– Collaborating registries to collect community-specific

schemas and to share the schemas among communities– Software tools attached to a registry, e.g.

• Vocabulary maintenance tool attached to a registry,• Metadata application software generator