SemanTic%20Interoperability%20To%20access%20Cultural%20Heritage

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SemanTic Interoperability To access Cultural
Heritage

• Frank van Harmelen
• Henk Matthezing
• Peter Wittenburg
• Marjolein van Gendt
• Antoine Isaac
• Lourens van der Meij
• Stefan Schlobach
• Paul Doorenbosch

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CH Interoperability Problems

• Current CH trend portals that build on
  heterogeneous collections
• Different databases/vocabularies/MD schemes

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CH Interoperability Problems

• Current CH trend portals that build on
  heterogeneous collections
• Different databases/vocabularies/MD schemes
• Syntactic interoperability problem being solved?
• Access can be granted
• Semantic interoperability still to be addressed
• Links with original vocabularies/MD structures
  are lost

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STITCH General Goals

• Allow heterogeneous CH collections to be accessed
• In an integrated way
• Still benefiting from specific collection
  commitments
• Keeping original metadata schemes and
  vocabularies
• Using Semantic Web means for
• Representation of different points of view in one
  system
• Creation and use of alignment knowledge

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STITCH General Goals (2)

• Research objective develop theory, methods and
  tools for allowing metadata interoperability
  through semantic links between vocabularies
• Formalization of schemes (and collections)
• Applying ontology mapping techniques to those
  schemes
• Using the results of the mappings in formal
  reasoning mechanisms (and dedicated interfaces)

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Applying SW research to concrete objectives

• Specificity of resources (thesauri, metadata
  schemes)
• Formalization in a context of natural semantics
• What can ontology mapping techniques bring to
  solve the interoperability problem in CH?
• Quantitative and qualitative evaluation
• Integration into realistic scenarios
• Are these techniques really applicable to the CH
  case?
• Uses that have to be further specified
• What does accessing collections in an integrated
  way mean?
• Interfaces, services?
• Anticipating needs that are not yet stabilized

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Pilot Project

• Experiment on a reduced scale
• Choose and formalize 2 collections and their
  associated subject vocabularies
• Rijksmuseum ARIA Masterpieces and its catalogue
• KB Illustrated Manuscripts and Iconclass
• Use existing mapping tools to align vocabularies
• Adapt/develop a browsing interface providing an
  integrated access using
• Original vocabularies and their structure
• Alignment information

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1st Collection KB Illustrated Manuscripts
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2nd Collection Rijksmuseum ARIA collection
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PP Modules
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PP Modules
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Collection Formalization Goals

• Analysis of the vocabularies and MD structures
• Representation using SW languages
• Testing standard means (SKOS/RDF)
• Conversion for vocabularies, but also for
  metadata structures
• Ontologies providing proper collection-related
  relations
• Conversion for interface and reasoning engine
  (application-specific) but also for formal
  ontology mapping tools

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Vocabulary Formalisation ARIA in SKOS
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Collection Formalization Problems

• Interpreting and representing vocabularies using
  formal standards is hindered by expressivity
  variation
• Complex models
• Fuzzy structures, weakly structured
• Implies some loss of data during standardisation?
• Part of the formalization is system-specific
• Depending on application environment
• Standard RDFS expressivity and implemented tools
• Depending on the mapping tools, which might make
  different hypotheses on the nature of knowledge
  to align
• OWL classes vs. nodes in trees
• Changes the role of the standard representation
  in the system?

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PP Modules
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Automatic Ontology Matching Techniques

• Generally aiming at recognizing equivalence or
  subsumption links between ontology elements
• Lexical
• Labels of entities, textual definitions
• Structural
• Structure of the formal definitions of entities,
  position in the hierarchy
• Statistical
• Objects, instantiation of the concepts
• Shared background knowledge (oracles)
• Using conceptual references to deduce
  correspondences
• Most mapping tools use a mix of such approaches
• E.g. lexical string matching can ignite a
  structural alignment process

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Collection Integration Goals

• Provide mappers with proper resources
• Pre-processing done in previous step
• Use them in the most efficient way
• Setting taking into account the specificities of
  CH vocabularies
• Evaluation/selection of their results
• Taking into account the use of CH vocabularies in
  their collection
• Use their result in the application system
• Post-processing
• Do it for vocabularies but also for metadata
  schemes
• Not in pilot

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Mappings
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Mappings
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Collection Formalization Problems

• Input needs pre-processing, possibly division
• Output needs re-interpretation of mapping
  relations
• Can confidence measures be used?
• Alignment process
• Usually turning to resources that may be absent
  from thesauri
• Rich formal/structural information
• Dually indexed documents
• Not (properly) using all information found in
  thesauri
• E.g. rich lexical information
• Leading to low-quality thesaurus mapping

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PP Modules
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User Interface Access to Collections

• Adapted faceted browsing paradigm (Flamenco)
• Search by navigating through several facets
• STITCH PP facet adaptation
• From orthogonal facets (material, location)
  to facets describing different conceptual schemes
  (ARIA, Iconclass)
• 3 views on integrated collections
• Single view
• Combined view
• Merged view
• http//stitch.cs.vu.nl

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Collections Access Single View

• Facets based on 1 point of view and its
  associated concept scheme(s)
• Access to objects indexed against concepts from
  other schemes
• If mapping between their index and the concepts
  from single view
• A single point of view on integrated data set

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Collections Access Combined View

• Search based on 2 (or more) points of view
• One facet uses 1 vocabulary from 1 point of view
• Facets attached to the different points of view
  are presented
• Simultaneous access to different points of view
  of the same data

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Collections Access Merged View

• Facets using a merged concept scheme
• Mapping leads to hierarchical links between
  schemes
• Making the links between vocabularies more
  visible during search
• A way to enrich weakly structured vocabularies

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Collection Access Conclusion

• Prototype is thin layer on top of SW/RDF
  technology (using Sesame)
• All data is stored in and retrieved from RDF
  repositories
• Easily adaptable for experimentation with
  different views (without programming)
• For convincing results you need good quality
  mapping
• E.g., to assess the value of Merged view
• Towards application-specific evaluation criteria?