Notes on ThoughtLab / Athena WP4

November 13, 2009

Antoine Isaac

aisaac@few.vu.nl

Towards semantics-enabled search

• Enhance access to Europeana content by semantics

• Exploiting different types of relations– locatedIn, isBornIn, created…

• Making use of inference– Finding work showing London for a query on UK

• Rich descriptions are already there, in metadata!• Requires to make it properly machine-accessible

Goal: semantics in Europeana v1.0

Building a semantic layer to help accessing content

Stefan Gradmann, EDL D2.5

Europeana Thought Lab

http://europeana.eu/portal/thought-lab.html

Semantic autocompletion

Clustering of results

Baseline: matching concepts' label

A "more specific Egypte"??

A "more specific Egypt"?

A concept more specific than the Egypt one

Following other relations

Following other relations - creator

Following other relations - match

Following other relations – death place

Following other relations – death place

Enabling Technologies

• RDF– Uniform format for data– Amenable to sharing and linking

• OWL – Representation of metadata structures– Amenable to inference

• SKOS– Representation of controlled vocabulary– Allows exploitation of legacy knowledge organization

• Simple but precious!• E.g., hierarchical relationships for cluster creation

Where are the challenges?

• Semantic conversion of data– Using appropriate data models– Enriching legacy metadata

• Semantic alignments– Between description ontologies

vra:depicts rdfs:subPropertyOf dc:subject

– Between concepts in controlled vocabulariesiconclass:bird skos:closeMatch ddc:bird

Alignment of semantic references

Where are the challenges?

• Semantic alignment (c'ed)– Find correspondences between large vocabularies– In a multilingual context

Athena WP4

Seems to fit very nicely into that challenge

• SKOS & SKOSification• Semantic alignment:

From Marie-Véronique & Johann, Lund

"The Athena Thesaurus = network of Athena-compliant micro-thesauri with bridges in-between"

• Focus on multilingual resources

What kind of semantic alignment?

• Fundamental goal:– enhancing semantic interoperability of collections– via the KOSs used for describing them

• Several options…

Structural models for interoperability(British Standard BS8723)

1. Unified structure: one KOS

2. Pairwise relations

3. Backbone structure

VocA

VocB

VocC

VocD

VocB

VocC

VocD

VocA

Structural models for interoperability

ThoughtLab "data cloud"• Not really corresponding to best practice

– More like a "web of data" cloud

• But still, a couple of backbone/central nodes– Again, like a "web of data" cloud

• At some point, we have to deal with what is there• Especially if it's much better than nothing!

Goals of Athena WG4?

• Athena Integrated Thesaurus • or Athena Thesaurus Network?

VocA

VocB

VocC

VocD

AthenaThesaurus

VocC

VocD

VocA

Throwing away integrated thesaurus?

• Individual manual mappings can already be exploited– Dumping them in the semantic layer will bring interesting stuff

• Keeping original vocabularies as access points can be an asset

• But a backbone for museum KOSs is likely to bring more– Especially as an umbrella for all those small controlled lists!

• An unified multilingual thesaurus is always extremely precious to have

Throwing away integrated thesaurus?

Thesaurus integration can be used as a driving scenario

• Issue: mapping without application in mind is tricky– What's the "meaning" of a concept?– archeology; netherlands can perfectly be mapped to excavations for translation of book annotations at KB

• Thesaurus integration can provide with mapping criteria– Two concepts are equivalent if we can fit them in the same place

of a semantic network

Wishlist?

• Again, do not forget that intermediate results (individual mappings) can be very precious

• If you produce them as part of the process anyway, there should be a way to export them– As SKOS?

• Problem: ideally, this would require SKOS versions of the individual "micro-thesauri"– Is that planned?

Thanks!