SKOS xtech2005

SKOSA language to describe simple knowledge structures for the web: 

SKOS A language to describe simple knowledge structures for the web Alistair Miles, CCLRC Brian Matthews, CCLRC Dave Beckett, ILRT Dan Brickley, W3C Michael Wilson, CCLRC Nikki Rogers, ILRT Semantic Web Best Practices and Deployment

Supporting material: 

Supporting material http://wiki.usefulinc.com/User:Aliman Links to … Paper of this presentation SKOS Core Guide SKOS Core Vocabulary Specification Quick Guide to Publishing a Thesaurus

Purpose of this talk: 

Purpose of this talk Introduce ‘SKOS Core’ and … … find out what you think. N.B. SKOS Core recently published as W3C first public working draft … … so this is a work in progress.

Context: 

Context Textual content-based web search engines are limited Meaningful metadata can improve information retrieval & management Metadata requires shared ‘vocabularies’ of concepts E.g. AAT, DDC E.g. DMOZ, Topic Exchange To support exchange, re-use, need a simple language for expressing ‘vocabularies’ of concepts in machine-understandable way

SKOS Core: 

SKOS Core ‘Simple Knowledge Organisation System’ SKOS Core … Tool for publishing descriptions of concepts, simple knowledge structures Application of RDF Cf. OWL … OWL is a sledge hammer SKOS Core is a nut cracker In fact complement each other, can be used in combination to optimise cost/benefit ratio

Background: 

Background Libraries use classification schemes, thesauri, subject headings, taxonomies etc. ISO 2788-1986, ISO 5964-1985 DESIRE project RDF schema for thesauri LIMBER project RDF Thesaurus Interchange Format (TIF)

Background: 

Background SWAD-Europe (EU IST 5FP) Simple Knowledge Organisation System (SKOS) Rename from TIF to SKOS … Extend scope Not just interchange RDF is not a file format, but a formalism for distributed data management W3C SWBPD-WG Manages SKOS Core Public Working Drafts (10 May 2005) SKOS Core Guide SKOS Core Vocabulary Specification Quick Guide to Publishing a Thesaurus on the Semantic Web

SKOS Development: 

SKOS Development ‘Open source’ Public mailing list public-esw-thes@w3.org Wiki http://esw.w3.org/topic/SkosDev Initial success due to community involvement

Basic Examples: 

Basic Examples Glossary Taxonomy Thesaurus

Examples Note: 

Examples Note

Glossary: 

Glossary Assertion (i) Any expression which is claimed to be true. (ii) The act of claiming something to be true. Class A general concept, category or classification. Something used primarily to classify or categorize other things. Resource (i) An entity; anything in the universe. (ii) As a class name: the class of everything; the most inclusive category possible. From RDF Semantics Glossary:

Glossary: 

Glossary

Glossary: 

Glossary

Glossary: 

Glossary Glossary example illustrates … Concept (class) definition (property) prefLabel (property)

Taxonomy: 

Taxonomy General Travelling Politics SemWeb RDF OWL From MortenF’s weblog categories …

Taxonomy: 

Taxonomy

Taxonomy: 

Taxonomy

Taxonomy: 

Taxonomy Taxonomy example illustrates … broader (property) narrower (property)

Thesaurus: 

Thesaurus Term: Economic cooperation Used For: Economic co-operation Broader terms: Economic policy Narrower terms: Economic integration, European economic cooperation, European industrial cooperation, Industrial cooperation Related terms: Interdependence Scope Note: Includes cooperative measures in banking, trade, industry etc., between and among countries. From UK Archival Thesaurus …

Thesaurus: 

Thesaurus

Thesaurus: 

Thesaurus Thesaurus example illustrates … altLabel (property) scopeNote (property) related (property)

SKOS Core Overview: 

SKOS Core Overview Basic description Concept, ConceptScheme, inScheme, hasTopConcept Labelling prefLabel, altLabel, hiddenLabel, prefSymbol, altSymbol … (audio labels?) Documentation definition, scopeNote, changeNote, historyNote, editorialNote, publicNote, privateNote Semantic relations broader, narrower, related Subject indexing subject, isSubjectOf, primarySubject, isPrimarySubjectOf Grouping Collection, OrderedCollection, CollectableProperty, member, memberList

SWED Portal: 

SWED Portal Application of SKOS Core for faceted browsing SKOS Core used to describe relevant concepts shared by community Environmental organisations publish description of themselves (metadata) Portal aggregates metadata

Combining SKOS Core with …: 

Combining SKOS Core with …

Extensibility (1): 

Extensibility (1) ‘Extension’ by combination Not ‘take it or leave it’ … But ‘take what you want, create what you need’

Extension (2): 

Extension (2) Extension by refinement E.g. SWED areas of operation … Define refinements (sub-properties) of SKOS Core semantic relation properties E.g. AAT fundamental facets Define refinements (sub-classes) of the skos:Concept class When using ‘extension by refinements’ each class or property of SKOS Core is an ‘extension point’, with extensions guaranteed to be backwards compatible by RDFS inference

GEMET: 

GEMET E.g. GEMET ‘non-standard’ thesaurus

Fundamental Facets: 

Fundamental Facets E.g. the AAT …

SKOS World View: 

SKOS World View

Open questions …: 

Open questions … Relationship to RDFS/OWL ontologies … tti … ? ‘Subject indicators’ …

SKOS & web services: 

SKOS & web services Interact with large published datasource … SPARQL query … More specific functionality … ? SKOS API

WS & SW … ?: 

WS & SW … ?

Summary: 

Summary SKOS Core simple RDF language for describing and publishing ‘vocabularies’ of concepts on the (semantic) web Glossaries, taxonomies, thesauri … Extensible, flexible Application e.g. SWED, GEMET WS API ?