1UNEP Terminology Workshop - Geneva, April 15, 2004

EnvironmentalTerminology & ThesaurusWorkshop

UN Environment Programme Regional Office of Europe Geneva, April 14-15, 2004

bernard.vatant@mondeca.com

Ontology and Thesaurus Integration in a Semantic Web Framework

Use Case : Multimedia Dictionary of Sustainable Development

2UNEP Terminology Workshop - Geneva, April 15, 2004

TerminologyThesaurus, Glossary ...

Knowledge ObjetsClasses, Individuals ...

Information ResourcesDocuments, Data ...

SemanticInteroperability ?

IndexTaxonomies ...

KOSOntologies ... Metadata

Big Picture : Things we are about

Different views of the world, different technologies … But : ‘Everything is a Thing’ : concepts, objects, resources ...

3UNEP Terminology Workshop - Geneva, April 15, 2004

Semantic Interoperability Issues

Identification of things How do we agree we are speaking about the same thing?

Inside the same KOS Across distributed systems

How do we access distributed information about a given thing?

Ontology Commitment How do we agree on classes and properties of things? How formal is this agreement? (for humans - for computers)

Knowledge Organisation How are things related to each other?

Metadata Definition What things are our documents and data about?

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Semantic Web Quick Answers

Identification of things Things are represented and identified by URIs

“Everything” can be represented and identified that way

Ontology Commitment OWL provides standard ways to declare, and commit to, an ontology

Based on RDF-XML syntax and RDF semantics

Knowledge Organisation RDF allows linking of resources using ‘semantic predicates’

Whatever the kinds of things represented

Metadata Definition RDF is the common metadata format

Supported by current Web environment and technologies (XML)

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Some added value from Topic Maps

Topic Maps bring features not native in RDF+OWL Multilingual Management

Using Name + Scope mechanism Subject Indicators

Supposed to clarify which subject an URI actually identifies But there is still debate about how a subject indicator defines identity ...

• Identity = identifying properties + identification context N-ary relationships

Native Topic-Role-Association structures Allow natural expression of Knowledge Base complex relationships

Like Thesaurus, Topic Maps have no built-in formal semantics Can be a strength or a weakness

Pro : flexibility, intuitive model and navigation paradigm Con : no formal model, no standard support for inference

6UNEP Terminology Workshop - Geneva, April 15, 2004

Porting Thesaurus to the Semantic Web

Dealing with Thesaurus legacy How to make a Thesaurus usable in a Semantic Web framework?

How to declare - implicit or explicit - Thesaurus semantics? Which languages fit the best?

RDF? RDFS? OWL? Topic Maps? SKOS? What are the current standard or best practices?

No ‘standard’ answer(s) to those questions ...

Ongoing work in W3C Semantic Web Activity and WGs SWAD-Europe Thesaurus Activity : SKOS Semantic Web Best Practices and Deployment Working Group

“Porting Thesaurus to the SW” is one of the top-priority tasks

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Thesaurus vs Ontology : FAQ Is not my Thesaurus a (weak, casual, unformal) kind of ontology?

Yes, a Thesaurus defines concepts and relationships between them• But provides no formal definition of meaning of relationships

Can I make my Thesaurus more formal? Sure, most of the time one can easily explicit some implicit semantics

• e.g. BT-NT may stand for Whole-Part, or Agent-Action, Class-Instance ...

What will users gain from more explicit semantics? Consider the trade-off between formalism and usability

• For human navigation purpose, formal semantics are barely useful• For machine inference, formal semantics are needed

So, should I transform my Thesaurus into an ontology, and throw away the old stuff altogether?

Don’t do that! Thesaurus should be integrated in, not destroyed by the SW infrastructure

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Ontology

Topic Map

Ontology-Driven Knowledge Base

Rules

Constraints

Classes

Instances

Data 1953-04-21

Bernard VatantMondeca AR1 R2

OrganisationEmployeeEmployer

Employment

Person

In an Employment AssociationThe Employer role is played by an OrganisationThe Employee role is played by a Person

homePage birthDate

www.mondeca.com

9UNEP Terminology Workshop - Geneva, April 15, 2004

Ontology

Topic Map

Ontology-Driven Thesaurus

Rules

Constraints

Classes

Instances

Data The northernmost area of the Earth ...

Arctic RegionPolar Region AR1 R2

Geo-ConceptPartWhole

Partitive

Geo-Concept

In a Geographical Partitive AssociationThe Whole role is played by a Geographical ConceptThe Part role is played by a Geographical Concept

Definition Definition

Area relating to the Earth's poles...

10UNEP Terminology Workshop - Geneva, April 15, 2004

Technology Integration Use-Case

2002 Q1 : Prototype project Integration in Mondeca ITM of several KOS

GEMET Thesaurus (translation in XTM - made in Mondeca) UNEP priorities for 2002 Earth Summit Planète-Ecologie Directory of Web Resources

In the same Topic Map framework

2004 Q1 : Full-scale project Dictionnaire Multimédia du Développement Durable Same framework and objectives as in the prototype, plus

Control of all components (including Thesaurus) by a customized ontology• Concept tested in two ongoing FP5 projects : Hi-Touch and MOSES

Workspaces customization• Specific groups of users access and edit specific resources and metadata

Extensible to any relevant wider scope (ontology and content) And open to any proposal ...

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References

Semantic Web Best Practices and Deployment Working Group http://www.w3.org/2001/sw/BestPractices/

Topic Maps standards http://www.isotopicmaps.org

Ontology Editor Protégé-2 http://protege.stanford.edu/plugins/owl/

Mondeca http://www.mondeca.com

Dictionnaire multimédia du Développement Durable http://www.planetecologie.org/forumdd/Dicdevdur.html