UNEP Terminology Workshop - Geneva, April 15, Environmental Terminology & Thesaurus Workshop UN Environment Programme Regional Office of Europe Geneva, April 14-15, 2004 Ontology and Thesaurus Integration in a Semantic Web Framework Use Case : Multimedia Dictionary of Sustainable Development

UNEP Terminology Workshop - Geneva, April 15, Terminology Thesaurus, Glossary... Knowledge Objets Classes, Individuals... Information Resources Documents, Data... Semantic Interoperability ? Index Taxonomies... KOS Ontologies... Metadata Big Picture : Things we are about Different views of the world, different technologies … But : ‘Everything is a Thing’ : concepts, objects, resources...

UNEP Terminology Workshop - Geneva, April 15, Semantic Interoperability Issues Identification of things q How do we agree we are speaking about the same thing? o Inside the same KOS o Across distributed systems q How do we access distributed information about a given thing? Ontology Commitment q How do we agree on classes and properties of things? q How formal is this agreement? (for humans - for computers) Knowledge Organisation q How are things related to each other? Metadata Definition q What things are our documents and data about?

UNEP Terminology Workshop - Geneva, April 15, Semantic Web Quick Answers Identification of things q Things are represented and identified by URIs o “Everything” can be represented and identified that way Ontology Commitment q OWL provides standard ways to declare, and commit to, an ontology OWL o Based on RDF-XML syntax and RDF semantics Knowledge Organisation q RDF allows linking of resources using ‘semantic predicates’ RDF o Whatever the kinds of things represented Metadata Definition q RDF is the common metadata format o Supported by current Web environment and technologies (XML)

UNEP Terminology Workshop - Geneva, April 15, Some added value from Topic Maps Topic MapsTopic Maps bring features not native in RDF+OWL q Multilingual Management o Using Name + Scope mechanism q Subject Indicators o Supposed to clarify which subject an URI actually identifies o But there is still debate about how a subject indicator defines identity... Identity = identifying properties + identification context q N-ary relationships o Native Topic-Role-Association structures o Allow natural expression of Knowledge Base complex relationships Like Thesaurus, Topic Maps have no built-in formal semantics q Can be a strength or a weakness o Pro : flexibility, intuitive model and navigation paradigm o Con : no formal model, no standard support for inference

UNEP Terminology Workshop - Geneva, April 15, Porting Thesaurus to the Semantic Web Dealing with Thesaurus legacy q How to make a Thesaurus usable in a Semantic Web framework? o How to declare - implicit or explicit - Thesaurus semantics? q Which languages fit the best? o RDF? RDFS? OWL? Topic Maps? SKOS? o What are the current standard or best practices? No ‘standard’ answer(s) to those questions... Ongoing work in W3C Semantic Web Activity and WGs q SWAD-Europe Thesaurus Activity : SKOS SWAD-EuropeThesaurus ActivitySKOS q Semantic Web Best Practices and Deployment Working Group Semantic Web Best Practices and Deployment Working Group o “Porting Thesaurus to the SW” is one of the top-priority tasks

UNEP Terminology Workshop - Geneva, April 15, Thesaurus vs Ontology : FAQ q Is not my Thesaurus a (weak, casual, unformal) kind of ontology? o Yes, a Thesaurus defines concepts and relationships between them But provides no formal definition of meaning of relationships q Can I make my Thesaurus more formal? o 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... q What will users gain from more explicit semantics? o Consider the trade-off between formalism and usability For human navigation purpose, formal semantics are barely useful For machine inference, formal semantics are needed q So, should I transform my Thesaurus into an ontology, and throw away the old stuff altogether? o Don’t do that! o Thesaurus should be integrated in, not destroyed by the SW infrastructure

UNEP Terminology Workshop - Geneva, April 15, Ontology Topic Map Ontology-Driven Knowledge Base Rules Constraints Classes Instances Data Bernard VatantMondeca A R1R2 Organisation Employee Employer Employment Person In an Employment AssociationEmployment The Employer role is played by an Organisation The Employee role is played by a Person homePage birthDate

UNEP Terminology Workshop - Geneva, April 15, Ontology Topic Map Ontology-Driven Thesaurus Rules Constraints Classes Instances Data The northernmost area of the Earth... Arctic RegionPolar Region A R1R2 Geo-Concept Part Whole Partitive Geo-Concept In a Geographical Partitive Association The Whole role is played by a Geographical Concept The Part role is played by a Geographical Concept Definition Area relating to the Earth's poles...

UNEP Terminology Workshop - Geneva, April 15, Technology Integration Use-Case 2002 Q1 : Prototype project q Integration in Mondeca ITM of several KOS o GEMET Thesaurus (translation in XTM - made in Mondeca) o UNEP priorities for 2002 Earth Summit o Planète-Ecologie Directory of Web Resources q In the same Topic Map framework 2004 Q1 : Full-scale project q Dictionnaire Multimédia du Développement Durable Dictionnaire Multimédia du Développement Durable q Same framework and objectives as in the prototype, plus o Control of all components (including Thesaurus) by a customized ontology Concept tested in two ongoing FP5 projects : Hi-Touch and MOSES o Workspaces customization Specific groups of users access and edit specific resources and metadata q Extensible to any relevant wider scope (ontology and content) o And open to any proposal...

UNEP Terminology Workshop - Geneva, April 15, References Semantic Web Best Practices and Deployment Working Group q Topic Maps standards q Ontology Editor Protégé-2 q Mondeca q Dictionnaire multimédia du Développement Durable q