Valentine Charles (Europeana) “Linking cultural heritage with KOS: the Europeana example” Presentation at the KnoweScape workshop "Evolution and variation of classification systems" March 4-5, 2015 Amsterdam

1. Linking cultural heritage with KOS
the Europeana example
Valentine Charles
Evolution and variation of classification systems – KnoweScape, Amsterdam,
05.03.2015

2. Context
à Aggregates metadata from the cultural heritage sector in
Europe
• Libraries, museums, archives and audio-visual archives
• Metadata in 33 languages
à Provides a portal for users to access data and objects
• http://www.europeana.eu/ in 31 languages
• Metadata under Creative Commons Zero - public domain
• Previews and links to source
à Data distributed via
• API http://labs.europeana.eu/api/
• Linked Data (currently being updated) http://data.europeana.eu/

3. Europeana.eu, Europe’s cultural heritage portal
40M objects from 2,200 galleries, museums, archives and libraries

4. Create a new data framework for richer
metadata
à Europeana Data Model (EDM)
• Re-uses several existing Semantic Web-based models: Dublin
Core, OAI-ORE, SKOS, CIDOC-CRM…
• More granular metadata
• links e.g. between objects and context entities (persons, places)
• multilingual & semantic linked data for contextual resources (e.g.
Concepts)
à EDM gives support for contextual resources (semantic layer)

5. Rely on KOS to solve a problem of data
integration
à Create a “semantic layer” on top of connected cultural
heritage objects
• Include multilingual “value vocabularies”
• From Europeana’s providers or from third-party data sources

6. Contextual entities
Representing (real-world) entities related to a provided object
as fully fledged resources, not just strings
edm:Agent
foaf:name
skos:altLabel
rdaGr2:biographicalInformation
rdaGr2:dateOfBirth
skos:Concept
skos:prefLabel
skos:altLabel
skos:broader
skos:related
skos:definition….
edm:TimeSpan
skos:prefLabel
dcterms:isPartOf
edm:begin
edm:end
….
edm:Place
wgs84_pos:lat
wgs84_pos:long
skos:prefLabel
skos:note
dcterms:isPartOf….

7. Encourage data providers to contribute their
own vocabularies
à Benefit from data links made at data providers’ level
à Ingestion of vocabularies is made possible if the vocabularies used
the data structures EDM expects
• For instance SKOS for concept
à For other vocabularies, Europeana does custom mappings

9. An example the integration of AAT URIs in EDM
hourglasses@en uurglazen@nl
reloj de las
horas@es
http://vocab.getty.edu/aat/300206197
edm:ProvidedCHO
Hourglass
urn:imss:instrument:401058
skos:Concept
http://vocab.getty.edu/
aat/300198626
skos:prefLabel
skos:prefLabel
skos:prefLabel
skos:broader
dc:type

11. Demo with AAT and PartagePlus vocabularies
à http://www.europeana.eu/portal/search.html?
query=sabliers&rows=24&qf=PROVIDER%3A%22Museo+Galileo+-
+Istituto+e+Museo+di+Storia+della+Scienza%22&qt=false
à http://www.europeana.eu/portal/search.html?
query=Brooch&rows=24&qf=PROVIDER%3A%22Partage+Plus
%22&qt=false

12. Vocabularies currently supported by
Europeana

13. Challenge #1
à Europeana needs to regularly check that vocabularies have not
changed at source:
• Changes in concepts’ identifiers
• Changes in the description of concepts (which would require a new
mapping)

14. Challenge #2
à Some of the vocabularies supported by Europeana have
been developed by projects
• Issue of sustainability who maintains the vocabulary when the
project ends? What happens to the data?

15. Europeana also manages its own vocabulary–
WWI example
à Europeana developed a series of domain specific “sub-sites”
à Europeana 1914-1918 (http://www.europeana1914-1918.eu/ )
developed its own vocabulary based on a subset of LCSH
• Terms translated in 10 languages and linked to id.loc.gov
• Published in SKOS via the OpenSkos vocabulary service

17. http://data.europeana.eu/concept/loc/sh85148236

18. Challenge #3
à Creation of caches of existing LOD vocabularies
• Europeana needs to keep track of the updates at the vocabulary
provider side.
à The enrichment done on the Europeana side lives separately
from the source vocabulary.

19. Multilingual Access to Subjects (MACS)
à MACS project has produced manual and semi automatic
alignments between:
• Library of Congress Subject Heading (LCSH)
• RAMEAU
• Schlagwortnormdatei (SWD)
è 120,000 links created
à MACS is integrated in The European Library as links
included in all bibliographic data.

20. An example of a MACS
record before and after
additions by The
European Library :
- ARK identifiers
- LOD URIs

21. Enrichments
added through
MACS
The subject enriched
record in EDM for delivery
to Europeana

22. Automatic enrichment based on KOS
Goal: Contextualization which goes beyond
the scope of a particular platform
Object External Dataset
and Vocabulary

23. Automatic enrichment process in Europeana
• Metadata
fields in
resource
descriptions
• Selection of
potential rules
to match
• Matching the
values of the
metadata fields
to values of the
contextual
resources
• Adding
contextual links
• Selecting the
values from the
contextual
resource
• Augmentation of
the index with the
labels picked from
the vocabulary
Analysis
Linking
Augmentation

24. Vocabularies selection requirements
In the context of Europeana a target vocabulary should be:
à Technically available (through Linked Data or in dedicated
repositories), properly documented, and in open access;
à well-connected together, e.g. equivalent elements in other
vocabularies are indicated;
• Key to avoid duplication and redundancy
à Multilingual

25. Enrichment Types and Vocabularies
Enrichment Type Target vocabulary Source metadata fields
Places GeoNames dcterms:spatial,
dc:coverage
Concepts GEMET, DBpedia, dc:subject, dc:type
Agents DBpedia dc:creator, dc:contributor
Time Semium Time dc:date, dc:coverage,
dcterms:temporal,
edm:year

26. Europeana enrichment- an example

27. Challenge #4
à A significant change change in the target vocabulary implies
• an update of the retrieved RDF files and a new deployment of
the enrichment framework (and/or)
• An update of the enrichment rules

28. Challenge #5
à Europeana data providers might also perform enrichment on
their side
à Europeana has currently no mecanism to separate the
(curated) links to contextual resources by data providers from
(automatic) enrichments by providers.

29. Challenge #6
à Automatic enrichment has flaws and problems
• For instance linking any print to the physical “pressure” concept
because of its German “Druck” alternative label.
à Incorrect enrichments lead to
• Devaluation of curated metadata
• Loss of trust from providers
• Irrelevant search results
• Bad user experiences

30. To conclude
à Europeana continues to focus on pivot vocabularies such as
Wikidata, Agrovoc to improve its search and retrieval
services.
à We now investigates how to use more domains specific
vocabularies for dedicated services.
à We also work on the definitions of best practices and
evaluation methods for enrichment
• http://pro.europeana.eu/get-involved/europeana-tech/
europeanatech-task-forces/evaluation-and-enrichments

31. Thank you
Valentine Charles
valentine.charles@europeana.eu

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