Accessing Cultural Heritage Collections using Semantic Web Techniques Antoine ISAAC STITCH Project SIKS Semantic Web Seminar, Utrecht April 11 th, 2007

Accessing Cultural Heritage collections using Semantic Web techniques Background 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

Accessing Cultural Heritage collections using Semantic Web techniques Agenda Cultural Heritage and Semantic Web Two important issues Representing Cultural Heritage vocabularies on the Semantic Web Vocabulary alignment Demo

Accessing Cultural Heritage collections using Semantic Web techniques 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

Accessing Cultural Heritage collections using Semantic Web techniques KB Illustrated Manuscripts – Iconclass vocabulary

Accessing Cultural Heritage collections using Semantic Web techniques KB Illustrated Manuscripts

Accessing Cultural Heritage collections using Semantic Web techniques Some Needs for CH Collections (2) Communicating data to the outside world Web portals Integrating different collections Virtual collections The European Library, Geheugen van Nederland,

Accessing Cultural Heritage collections using Semantic Web techniques (Biased) Semantic Web Pointing at resources: documents, knowledge objects Enabling structured assertions Metadata about entities present on the Web Using vocabularies with defined semantics Ontologies: formal definitions of shared conceptual vocabularies RDF Schema /OWL

Accessing Cultural Heritage collections using Semantic Web techniques (Biased) Semantic Web Web-based resources allow division/sharing of document vocabulary metadata (doc3, hasSubject, Amsterdam) different owners & locations

Accessing Cultural Heritage collections using Semantic Web techniques 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

Accessing Cultural Heritage collections using Semantic Web techniques Important line of research Long-term projects MuseumFinland, eCulture, 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”

Accessing Cultural Heritage collections using Semantic Web techniques

Agenda Cultural Heritage and Semantic Web Two important issues Representing Cultural Heritage vocabularies on the Semantic Web Vocabulary alignment Demo

Accessing Cultural Heritage collections using Semantic Web techniques 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

Accessing Cultural Heritage collections using Semantic Web techniques 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,…

Accessing Cultural Heritage collections using Semantic Web techniques 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

Accessing Cultural Heritage collections using Semantic Web techniques 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.

Accessing Cultural Heritage collections using Semantic Web techniques 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

Accessing Cultural Heritage collections using Semantic Web techniques SKOS: Brinkman Trefwoorden (KB) geneeskunde RT geneesmiddelen NT kindergeneeskunde geneesmiddelen UF medicijnen kindergeneeskunde BT geneeskunde noot: kinderen ouder dan 12 vallen niet onder kindergeneeskunde medicijnen USE geneesmiddelen

Accessing Cultural Heritage collections using Semantic Web techniques SKOS: Brinkman Trefwoorden (KB) skos: = bk: =

Accessing Cultural Heritage collections using Semantic Web techniques SKOS: Brinkman Trefwoorden (KB) geneeskunde geneesmiddelen medicijnen kindergeneeskunde kinderen ouder dan 12 vallen niet onder kindergeneeskunde

Accessing Cultural Heritage collections using Semantic Web techniques Agenda Cultural Heritage and Semantic Web Two important issues Representing Cultural Heritage vocabularies on the Semantic Web Vocabulary alignment Demo

Accessing Cultural Heritage collections using Semantic Web techniques 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?

Accessing Cultural Heritage collections using Semantic Web techniques 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

Accessing Cultural Heritage collections using Semantic Web techniques Old situation

Accessing Cultural Heritage collections using Semantic Web techniques Vocabulary alignment STITCH aim: find correspondences between vocabulary elements “klassieke ruïnes” ≈ “landschap met ruïnes” “maagd Maria” = “Heilige Moeder”

Accessing Cultural Heritage collections using Semantic Web techniques New situation

Accessing Cultural Heritage collections using Semantic Web techniques Automatic alignment techniques Lexical Labels of entities and textual definitions Structural Structure of the formal definitions of entities, position in the hierarchy Statistical Object information (e.g. book indexing) Background knowledge Using a shared conceptual reference to find links brainLongtumor Long

Accessing Cultural Heritage collections using Semantic Web techniques Lexical alignment Use preferred labels, synonyms, notes Heuristic methods to discover equivalence and specialization relations Funeral ofPatroclus More specific than

Accessing Cultural Heritage collections using Semantic Web techniques Automatic Alignment Techniques Lexical Labels of entities and textual definitions Structural Structure of the formal definitions of entities, position in the hierarchy Statistical Object information (e.g. book indexing) Shared background knowledge Using a conceptual reference to deduce correspondences brainLongtumor Long

Accessing Cultural Heritage collections using Semantic Web techniques Statistical alignment

Accessing Cultural Heritage collections using Semantic Web techniques 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 Results 1: Schilderijen - schilderkunst 2: Kwaliteitszorg - kwaliteitsmanagement 3: Personeelsmanagement - personeelsbeleid... 17: Diabetes mellitus - suikerziekte

Accessing Cultural Heritage collections using Semantic Web techniques Agenda Cultural Heritage and Semantic Web Two important issues Representing Cultural Heritage vocabularies on the Semantic Web Vocabulary alignment Demo

Accessing Cultural Heritage collections using Semantic Web techniques Demo KB Illuminated Manuscripts French National Library Mandragore Manuscripts

Accessing Cultural Heritage collections using Semantic Web techniques Manuscripts, 2 nd Collection: BNF Mandragore

Accessing Cultural Heritage collections using Semantic Web techniques Manuscripts, 2 nd Collection: BNF Mandragore

Accessing Cultural Heritage collections using Semantic Web techniques Demo mandraNewNONE, amphibianshttp://stitch.cs.vu.nl/rp33333/MANDRA-SV-ICE- mandraNewNONE MANDRA-mandraNewNONE, wheathttp://stitch.cs.vu.nl/rp33333/MANDRA-SV- MANDRA-mandraNewNONE

Accessing Cultural Heritage collections using Semantic Web techniques 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

Accessing Cultural Heritage collections using Semantic Web techniques Thanks!

Accessing Cultural Heritage collections using Semantic Web techniques Links Semantic Web at Vrije Universiteit SKOS Other Cultural Heritage and Semantic Web projects MuseumFinland, eCulture,