Thesauri Terminologies and the Semantic Web A J

Thesauri, Terminologies and the Semantic Web A J Miles Rutherford Appleton Laboratory

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 A J Miles 22

SWAD-E • Semantic Web Advanced Development for Europe (SWAD-E) • EU Project • W 3 C Semantic Web Activity – R&D – Demos & Apps – Guidelines & Best Practises • Partners: HP Labs, ILRT, Stilo, ERCIM (INRIA), CCLRC A J Miles 33

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 A J Miles 44

SWAD-E Thesaurus Activity • Why is SWAD-E interested in thesauri? – Large body of well-engineered knowledge Þ Enrich & bootstrap semantic web • SWAD-E Thesaurus Activity – Design Schemas for thesaurus data – Guidelines for use and migration – Supporting technologies and demos A J Miles 55

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. A J Miles 66

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 Þ Can create large linked thesaurus structures – superthesauri Þ Linking solves problem of concurrent versions A J Miles 77

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] A J Miles 88

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 A J Miles 99

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 skos: semantic. Relation sub-property of skos: broader. Instantive Þ Infer meaning of concept from labels, scope notes, definitions, depictions & neighbours. A J Miles 10 10

SKOS Meta-Model A J Miles 11 11

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: broader. Theme • Sub-property of skos: broader – Property gemet: broader. Group • Sub-propery of skos: broader A J Miles skos: semantic. Relation sub-property of skos: broader sub-property of gemet: broader. Group 12 12

Approach to Non-Standard Thesauri • Design schema as extension to SKOSCore Þ Preserve unique features Þ Can interoperate with anything based on SKOS-Core Þ Have your cake and eat it! A J Miles 13 13

Example: Me. SH • Medical Subject Headings • Thesaurus features: – Semantically ambiguous concept hierarchy • Ontology features: – Semantic typing of concepts, e. g. Calcymycin type Antibiotic Þ 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) A J Miles 14 14

Interoperability: Thesaurus Mapping • Common use-case: overlapping thesauri – Mappings support interchangeable use of overlapping thesauri • Introducing: SKOS-Mapping – RDF Schema for inter-thesaurus mapping A J Miles 15 15

SKOS-Mapping Sets of Resources in which Concept Occurs Exact Inexact Major Minor Partial Broad Narrow Ordered Combinators: A J Miles AND, OR, NOT 16 16

Data Interop Summary • SKOS-Core supports interoperability of KOS with variable structures • SKOS-Mapping supports interoperability of overlapping KOS A J Miles 17 17

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 A J Miles 18 18

Multilinguality (2) Analyse each language component Multilingual Labelling Interlingual Mapping A J Miles 19 19

GEMET Backbone in SKOS-RDF <skos: Concept rdf: about="c_3194"> <gemet: broader. Theme rdf: resource="t_9"/> <skos: narrower rdf: resource="c_1824"/> <skos: narrower rdf: resource="c_13150"/> <skos: narrower rdf: resource="c_13260"/> <skos: narrower rdf: resource="c_13177"/> <skos: narrower rdf: resource="c_13152"/> <skos: narrower rdf: resource="c_8308"/> <skos: in. Scheme rdf: resource=". . /GEMET"/> <skos: narrower rdf: resource="c_6793"/> <gemet: broader. Group rdf: resource="g_2504"/> <skos: narrower rdf: resource="c_3205"/> <skos: narrower rdf: resource="c_1025"/> <skos: narrower rdf: resource="c_13151"/> <skos: narrower rdf: resource="c_11044"/> <skos: narrower rdf: resource="c_3201"/> <skos: narrower rdf: resource="c_4478"/> <skos: narrower rdf: resource="c_6602"/> </skos: Concept> A J Miles 20 20

GEMET en labels in SKOS-RDF <skos: Concept rdf: about="c_3194"> <skos: pref. Label xml: lang="en-GB">finances</skos: pref. Label> <skos: definition xml: lang="en-GB">The monetary resources or revenue of a government, company, organization or individual. (Source: RHW)</skos: definition> </skos: Concept> A J Miles 21 21

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 A J Miles 22 22

SKOS API • SKOS API – Interface to terminology web service – Under development (pre-release is online) • Participate on public mailing list: public-esw-thes@w 3. org A J Miles 23 23

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 A J Miles 24 24

Future Issues • Social aspects – Semantic web technology supports community driven development of thesauri – But … validation? • Change Management – Versioning – Evolution A J Miles 25 25

Summary • Semantic Web Technologies are tools – SKOS-Core & SKOS-Mapping support data interoperability – SKOS API supports application interoperability • W 3 C Semantic Web Best Practises Working Group – Thesaurus Task Force A J Miles 26 26

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 A J Miles 27 27

Thank You • Links: SWAD-Europe Thesaurus Activity http: //www. w 3. org/2001/sw/Europe/reports/thes/ SKOS-Core 1. 0 Guide http: //www. w 3. org/2001/sw/Europe/reports/thes/1. 0/guide/ SKOS API http: //www. w 3. org/2001/sw/Europe/reports/thes/skosapi. html SKOS-Core 1. 0 Guidelines for Migration http: //www. w 3. org/2001/sw/Europe/reports/thes/1. 0/migrate/ Public Thesaurus Mailing list public-esw-thes@w 3. org W 3 C Semantic Web Activity http: //www. w 3. org/2001/sw/ SWAD-E Project http: //www. w 3. org/2001/sw/Europe/ A J Miles 28 28