a j miles rutherford appleton laboratory thesauri, terminologies and the semantic web
TRANSCRIPT
A J Miles
Rutherford Appleton Laboratory
Thesauri, Terminologies and the Semantic Web
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CCLRC
• Council for the Central Laboratory of the Research Councils (CCLRC)
• Big Science– Synchrotron Radiation Sources– Lasers– Pulsed Neutron Source
• Large-scale IT demands: tera-scale data, computation
• Strong IT R&D programme• BITD: Business and Information
Technology Department
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SWAD-E
• Semantic Web Advanced Development for Europe (SWAD-E)
• EU Project• W3C Semantic Web Activity
– R&D– Demos & Apps– Guidelines & Best Practises
• Partners: HP Labs, ILRT, Stilo, ERCIM (INRIA), CCLRC
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Semantic Web
• Current Web:– Web of information for humans
• Semantic Web:– Web of data for computers
• Why?– Automation, organisation, search
• Enabling technologies:– RDF: Resource Description Framework
• Data linking, low-level semantics– OWL: Web Ontology Language
• High-level semantics, inference
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SWAD-E Thesaurus Activity
• Why is SWAD-E interested in thesauri?– Large body of well-engineered knowledge
Enrich & bootstrap semantic web
• SWAD-E Thesaurus Activity– Design Schemas for thesaurus data– Guidelines for use and migration– Supporting technologies and demos
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Exploiting the Semantic Web
• What can you get out of the semantic web?– Integration & Connectivity– Data Interoperability– Application Interoperability
• N.B. The Semantic Web is a Tool.
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Integration & Connectivity
• Recurring use-case: high/low-level thesauri– E.g. GCL & Cultural Heritage thesauri– E.g. Gerry’s macro/micro thesauri
• RDF => Data linking Can create large linked thesaurus structures – super-
thesauri Linking solves problem of concurrent versions
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Data Interoperability
• Interoperability is a major goal
• Move to XML technologies is a step in the right direction
• But …– XML does not equal Interoperability
• [N.B. plethora of XML formats for thesauri]
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SKOS-Core: RDF Schema for Thesauri
• Introducing: SKOS-Core 1.0– RDF Schema for Thesauri– SKOS: Simple Knowledge Organisation Systems
• The First Challenge: coping with variety in thesaurus design and structure– Allow unique features– Support interoperability
• The Second Challenge: interoperating with/migrating to ontologies, taxonomies, classification schemes etc.
• N.B. The semantic web is where data collide
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SKOS Meta-Model
• SKOS Meta-Model: Concept-orientation– Concepts (given URIs)– Labels (pref, alt) (symbols)– Concept Schemes– Semantic Relations (extensible set)
• Broader, narrower, related …– Semantic Mappings (extensible set)
• Exact, inexact …– Scope notes, definitions, depictions
Infer meaning of concept from labels, scope notes, definitions, depictions & neighbours.
skos:semanticRelation
skos:broader
skos:broaderInstantive
sub-property of
sub-property of
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SKOS Meta-Model
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Example: GEMET
• Non-Standard Features:– Groups & Super-Groups– Themes
• Solution: Extend SKOS-Core:– Class gemet:Group
• Sub-class of skos:Concept– Class gemet:Theme
• Sub-class of skos:Concept– Property gemet:broaderTheme
• Sub-property of skos:broader– Property gemet:broaderGroup
• Sub-propery of skos:broader
skos:semanticRelation
skos:broader
gemet:broaderGroup
sub-property of
sub-property of
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Approach to Non-Standard Thesauri
• Design schema as extension to SKOS-Core Preserve unique features Can interoperate with anything based on SKOS-Core
Have your cake and eat it!
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Example: MeSH
• Medical Subject Headings• Thesaurus features:
– Semantically ambiguous concept hierarchy
• Ontology features:– Semantic typing of concepts, e.g. Calcymycin type Antibiotic
Use combination of SKOS and OWL to represent this hybrid structure
• RDF, SKOS & OWL means you can migrate a thesaurus to ontology merely by adding statements
• (No re-engineering or transformation is required)
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Interoperability: Thesaurus Mapping
• Common use-case: overlapping thesauri– Mappings support interchangeable use of overlapping
thesauri
• Introducing: SKOS-Mapping– RDF Schema for inter-thesaurus mapping
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SKOS-Mapping
Sets of Resources in which Concept OccursExact
InexactMajor
Minor
PartialBroad
Narrow
Ordered
Combinators: AND, OR, NOT
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Data Interop Summary
• SKOS-Core supports interoperability of KOS with variable structures
• SKOS-Mapping supports interoperability of overlapping KOS
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Multilinguality
• Analyse multilingual thesaurus into language components
• Multilingual Labelling– Use SKOS-Core– E.g. GEMET
• Inter-lingual Mapping– Use SKOS-Core + SKOS-Mapping– E.g. AAT, Merimee
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Multilinguality (2)
Analyse each language component
Multilingual Labelling
Interlingual Mapping
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Application Interoperability
• Move to modularisation and distribution via web services is step in the right direction
• But …– Web services does not equal application
interoperability
• Web service API– Community driven design– Endorsed by wider community
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SKOS API
• SKOS API– Interface to terminology web service– Under development (pre-release is online)
• Participate on public mailing list:[email protected]
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Web Service Implementation
• Reference Implementation of SKOS API– Leverage power of sem-web tools
• E.g. RDF Query• E.g. transitive closure of broader concepts
• SOAP Service– Back end: Sesame RDF Store– Modular design
• Semantic Web Services
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Future Issues
• Social aspects– Semantic web technology supports community driven
development of thesauri– But … validation?
• Change Management– Versioning– Evolution
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Summary
• Semantic Web Technologies are tools– SKOS-Core & SKOS-Mapping support data
interoperability– SKOS API supports application interoperability
• W3C Semantic Web Best Practises Working Group– Thesaurus Task Force
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SWAD-E & Eco-informatics
• Work with thesaurus developers and managers– Publish RDF encodings of current thesauri– Test design and coverage of SKOS-Core
• Community building for development of web service API
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Thank You
• Links:SWAD-Europe Thesaurus Activity
http://www.w3.org/2001/sw/Europe/reports/thes/SKOS-Core 1.0 Guide
http://www.w3.org/2001/sw/Europe/reports/thes/1.0/guide/SKOS API
http://www.w3.org/2001/sw/Europe/reports/thes/skosapi.htmlSKOS-Core 1.0 Guidelines for Migration
http://www.w3.org/2001/sw/Europe/reports/thes/1.0/migrate/
Public Thesaurus Mailing [email protected]
W3C Semantic Web Activityhttp://www.w3.org/2001/sw/
SWAD-E Project http://www.w3.org/2001/sw/Europe/