accessing cultural heritage collections using semantic web techniques antoine isaac stitch project...

Accessing Cultural Heritage Collections using Semantic Web Techniques

Antoine ISAACSTITCH Project

SIKS Semantic Web Seminar, UtrechtApril 11th, 2007

Accessing Cultural Heritage collections using Semantic Web techniques

Background

• CATCH@ NWO• Continuous Access To Cultural Heritage• 10 computer science projects applied to the CH field

• Personalization of access, image/text/audio analysis

• Integration of projects in CH institutes (museums, archives)

• STITCH • SemanTic Interoperability To access Cultural Heritage

• Exchanging and integrating metadata• Vrije Universiteit, Koninklijke Bibliotheek & Max

Planck Institute


Agenda

• Cultural Heritage and Semantic Web• Two important issues

• Representing Cultural Heritage vocabularies on the Semantic Web

• Vocabulary alignment

• Demo


Some Needs for CH Collections

• Representation of objects and knowledge about them • Pointing at collection artifacts: books…• Describing them: creating metadata

• Specific metadata structures (metadata schemes)• Controlled expert vocabularies (e.g. thesauri)

• Accessing artifacts using metadata • E.g. search using information contained in

thesauri


KB Illustrated Manuscripts – Iconclass vocabulary


KB Illustrated Manuscripts


Some Needs for CH Collections (2)

• Communicating data to the outside world• Web portals

• Integrating different collections• Virtual collections

• The European Library, http://www.theeuropeanlibrary.org

• Geheugen van Nederland, http://www.geheugenvannederland.nl


(Biased) Semantic Web

• Pointing at resources: documents, knowledge objects

• Enabling structured assertions• Metadata about entities present on the Web

• Using vocabularies with defined semanticsOntologies: formal definitions of shared conceptual

vocabulariesRDF Schema /OWL

<owl:Class rdf:about="#Bird"> <owl:disjointWith> <owl:Class rdf:about="#Mammals"/> </owl:disjointWith> <rdfs:subClassOf> <owl:Class rdf:ID="Animals"/> </rdfs:subClassOf> </owl:Class>

<Bird rdf:about="#tweety"/>


(Biased) Semantic Web

• Web-based resources allow division/sharing of • document• vocabulary• metadata

(doc3, hasSubject, Amsterdam)

differentowners & locations

http://www.kb.nl/eDepot

http://www.geo.org/voc/

http://www.ned.nl/doc3


Cultural Heritage Collections and Semantic Web

• Categorizing/classifying things

• Structuring descriptions

• Web-based approach

Semantic Web techniques are good candidates for representing and exploiting Cultural Heritage metadata


Important line of research

• Long-term projects• MuseumFinland, http://www.museosuomi.fi/ • eCulture, http://e-culture.multimedian.nl/

• Common portals to (many) collections

• Exploiting the data found in the original systems• Metadata content: place, date, creator…• Semantics of vocabularies used to create this

information• E.g. hierarchical information • “A Picture featuring a crow features a bird”


Agenda




• Demo


Representing CH vocabularies on the Semantic Web - Similarities

• Both ontologies and thesauri bring concept hierarchies

• giving the intended meaning of a vocabulary through links between its items

• “concept/term” ≈? owl:Class• “broader” ≈?

rdfs:subClassOf• “scope notes” ≈?

rdfs:comment


Representing CH vocabularies on the Semantic Web - Problems

• Thesauri designed for humans, no formal interpretation

• How to interpret a thesaurus in RDFS/OWL:• If “(Story of) Hercules” is a class, what are its instances?• Is “Hercules shooting Nessus” a subclass of “Love-affairs of

Hercules”?Thesaurus hierarchy: subsumption, mereological relation,

…


Representing CH vocabularies on the Semantic Web – Different approaches

• Ontologising• Cleaning thesaurus by distinguishing roles, kinds,

etc.• Cleaning the hierarchical links

• Representing knowledge found in sources as such• Informal knowledge represented in RDF/OWL formal

framework


SKOS

• Simple Knowledge Organization Systems• (Future) W3C standard

• Model to represent controlled and structured vocabularies on the Semantic Web• Compatible with community needs• Core model for representing thesauri, classification

schemes, etc.


SKOS

• Building blocks (ontology) to create XML/RDF data about controlled vocabularies• Classes Concept and ConceptScheme• Lexical properties

• prefLabel• altLabel

• Semantic properties • broader, narrower• related

• Properties for notes and comments• scopeNote• definition


SKOS: Brinkman Trefwoorden (KB)

075607204 geneeskunde RT geneesmiddelenNT kindergeneeskunde

075607220 geneesmiddelen UF medicijnen

075611791 kindergeneeskunde BT geneeskunde noot: kinderen ouder dan 12 vallen niet

onderkindergeneeskunde

medicijnen USE geneesmiddelen



skos: = http://www.w3.org/2004/02/skos/core#bk: = http://www.kb.nl/brinkman/

bk:075611791

kindergeneeskundekinderen ouder dan12 vallen niet onderkindergeneeskunde

bk:075607204

geneeskunde

bk:075607220

medicijnengeneesmiddelenskos:prefLabel

skos:scopeNote

skos:broader

skos:prefLabel

skos:related

skos:prefLabel skos:altLabel



<skos:Concept rdf:about="http://www.kb.nl/brinkman/bk075607204"><skos:prefLabel>geneeskunde</skos:prefLabel><skos:related rdf:resource="http://www.kb.nl/brinkman/bk075607220"/>

</skos:Concept><skos:Concept rdf:about="http://www.kb.nl/brinkman/bk075607220">

<rdf:type rdf:resource="&skos;Concept"/><skos:prefLabel>geneesmiddelen</skos:prefLabel><skos:altLabel>medicijnen</skos:altLabel>

</skos:Concept><skos:Concept rdf:about="http://www.kb.nl/brinkman/bk075611791">

<rdf:type rdf:resource="&skos;Concept"/><skos:prefLabel>kindergeneeskunde</skos:prefLabel><skos:broader rdf:resource="http://www.kb.nl/brinkman/bk075607204"/><skos:scopeNote>kinderen ouder dan 12 vallen niet onder

kindergeneeskunde</skos:scopeNote></skos:Concept>


Agenda




• Demo


Cultural Heritage Interoperability Problems

• Problem: integrating different databases/metadata schemes/vocabularies

• Syntactic interoperability can be solved• Common format: XML (RDF)• Common vocabulary model (SKOS)

• How about conceptual heterogeneity?


The semantic interoperability problem

• There is no standard thesaurus• We don’t really want it

different vocabularies for different expertise domains, traditions, tasks

• Consequence:• “klassieke ruïnes” vs. “landschap met ruïnes”• “maagd Maria” vs. “Heilige Moeder”

• Practical problem:• Searching for “Heilige Moeder” misses “maagd

Maria”• Unless we know both vocabularies


Old situation


Vocabulary alignment

• STITCH aim: find correspondences between vocabulary elements• “klassieke ruïnes” ≈ “landschap met ruïnes”• “maagd Maria” = “Heilige Moeder”


New situation


Automatic alignment techniques

• Lexical Labels of entities and textual definitions

• StructuralStructure of the formal definitions of entities, position in the

hierarchy

• StatisticalObject information (e.g. book indexing)

• Background knowledge Using a shared conceptual reference to find links

brainLong tumor tumorLong


Lexical alignment

• Use preferred labels, synonyms, notes• Heuristic methods to discover

equivalence and specialization relations

Funeral of Patroclus PatroclusMore specific than


Automatic Alignment Techniques

• Lexical Labels of entities and textual definitions

• StructuralStructure of the formal definitions of entities, position in the

hierarchy

• StatisticalObject information (e.g. book indexing)

• Shared background knowledge Using a conceptual reference to deduce correspondences

brainLong tumor tumorLong


Statistical alignment


Statistic approach: Koninklijke Bibliotheek case

• Situation: 2 overlapping collections indexed with different thesauri

• Comparison means: measuring overlap between concepts from the thesauri• Using the sets of books indexed by these concepts

• Results1: 9132.9 Schilderijen - schilderkunst

2: 8088.5 Kwaliteitszorg - kwaliteitsmanagement

3: 6232.7 Personeelsmanagement - personeelsbeleid

...

17: 3421.8 Diabetes mellitus - suikerziekte


Agenda




• Demo


Demo

• KB Illuminated Manuscripts• French National Library Mandragore

Manuscripts


Manuscripts, 2nd Collection: BNF Mandragore


Demo

• http://stitch.cs.vu.nl/rp33333/MANDRA-SV-ICE-mandraNewNONE , amphibians

• http://stitch.cs.vu.nl/rp33333/MANDRA-SV-MANDRA-mandraNewNONE, wheat


Conclusion: Semantic Web can help Cultural Heritage

• Representation of collections and associated expert vocabularies

• Semantic integration through correspondences between different vocabularies

New opportunities for exploiting cultural heritage information


Thanks!


Links

• Semantic Web at Vrije Universiteit• http://www.cs.vu.nl/ai/kr/• http://www.cs.vu.nl/bi/

• SKOS• http://www.w3.org/2004/02/skos/

• Other Cultural Heritage and Semantic Web projects• MuseumFinland, http://www.museosuomi.fi/ • eCulture, http://e-culture.multimedian.nl/

accessing cultural heritage collections using semantic web techniques antoine isaac stitch project...

Documents

semantic web pointing

semantic web compatible

semantic web similarities

cultural heritage vocabularies

outside world web portals

bird slide

comment slide

ch vocabularies