Linked Data for EuropeanaCultural Heritage: the Europeana approach

Linked Data for European Cultural Heritage: the Europeana approachValentine Charles | ISSN2016

Netherlands, Public Domain1660 - 1625, Rijksmuseum

AnonymousArrival of a Portuguese ship

Title hereCC BY-SA

Europeana?

Enriching Cultural Heritage Data with DBpedia

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Europeana Collections homepageEuropeana| CC BY-SA

Europeana EssentialsCC BY-SACC BY-SA

Linked Data for European Cultural Heritage: the Europeana approach

http://europeana.eu/

Title hereCC BY-SA

Title hereCC BY-SA

Europeana aggregation infrastructureEuropeana| CC BY-SA

Europeana?



http://pro.europeana.eu/share-your-data/

Europeana and its many data challenges

Enriching Cultural Heritage Data with DBpediaCC BY-SA

We aggregate very heterogeneous metadata

• More than 50M objects• 3,500 galleries, libraries, archives and museums• 50 languages• From all EU countries• Level of quality varies greatly



Europeana and the challenge of identifiers A manifold issue:

• Europeana needs to manage identifiers within its data aggregation workflow to

• Make sure identifiers are persistent• Limit the amount of duplicates

• Europeana collects a huge number of references to places, agents, concepts, time

• But most of them are represented as simple text strings






Title hereCC BY-SA

Title hereCC BY-SA

Linked Open Data

Europeana Linked Open Data video on VimeoEuropeana | CC BY-SA



https://vimeo.com/36752317

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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)

Building a framework for semantic cultural heritage data Europeana Essentials

CC BY-SACC BY-SALinked Data for European Cultural Heritage: the Europeana

approach

A data model to represent richer (linked) data

Create a “semantic layer” on top of cultural heritage objects

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• Include multilingual “value vocabularies”• From Europeana’ s providers or from third-party data sources

Building a framework for semantic cultural heritage data Europeana Essentials


approach

STRATEGIES FOR GETTING LINKED DATA

Concours de cycles nautiques sur le lac d’Enghien : Berregent piloté par Austerling

1914, National Library of FranceAgence de presse Meurisse

France, Public Domain

Encourage data providers to contribute their own vocabularies




• Benefit from data links made at data providers’ level

• Ingestion of vocabularies is made possible if the vocabularies used the data structures EDM expects

• For instance SKOS for Concepts• For other vocabularies, Europeana does custom

mappings

Semantic enrichment, a solution for better quality data? Automatic and manual enrichment are more and more commonly used in digital libraries to:

• normalise data

• “standardize data” by linking it to authority resources

• improve multilingual coverage in datasets

• contextualise resources

• contribute to build a web of data ('knowledge graph') that third parties can use to improve their users' experience




The main components of semantic enrichment

source objects whose metadata is being enriched set of resources

used to enrich the source metadata

targets can be of different types, from simple uncontrolled strings to resources published as LOD

specify how the enrichment between the source and target should be executed.

Source

Target

Rules

Enriching Cultural Heritage Data with DBpediaEuropeana EssentialsCC BY-SACC BY-SA


Automatic enrichment process in Europeana

selection of metadata fields in descriptions

selection of potential rules to match

matching the values of the metadata fields to values of the contextual resources

adding contextual links

selection of values from the contextual resource

values go into the search index

Analysis

Linking

Augmentation of search index

Enriching Cultural Heritage Data with DBpediaEuropeana EssentialsCC BY-SACC BY-SA


Building a framework for semantic cultural heritage data Europeana EssentialsCC BY-SACC BY-SA


Vocabularies we currently enrich metadata with

Enriching Cultural Heritage Data with DBpedia

Entity Class

Target vocabulary Size Metadata Fields subject of

Enrichment

Places GeoNames 140,097

dcterms:spatial, dc:coverage

Concepts DBpedia 5,284 dc:subject, dc:type

GEMET 280

Agents DBpedia 161,209

dc:creator, dc:contributor

Time Semium Time

2,566 dc:coverage, dcterms:temporal, dc:date, edm:year



Some challenges are harder than others !

France, Public Domain1588, Bibliothèque municipale de Lyon

Hendrik Goltzius

Le dragon dévorant les compagnons de Cadmus

Evaluation of metadata enrichment practices in digital libraries: steps towards better data enrichments

Poisonous India or the Importance of a Semantic and Multilingual Enrichment StrategyMarlies Olensky, Juliane Stiller, Evelyn Dröge, MTSR 2012 http://link.springer.com/chapter/10.1007%2F978-3-642-35233-1_25

Challenges of multilingual automatic enrichment

http://link.springer.com/chapter/10.1007/978-3-642-35233-1_25

http://link.springer.com/chapter/10.1007/978-3-642-35233-1_25

Available solutions: Define recommendations for semantic enrichment including

CC BY-SAEnriching Cultural Heritage Data with

DBpedia

• the selection of the targets datasets• the selection of the tool and method• the monitoring and evaluation of the enrichment

and its output

• http://bit.ly/Evaluation-Enrichment



http://bit.ly/Evaluation-Enrichment



Building an ecosystem of networked references

see http://cultuurlink.beeldengeluid.nlEuropeana Essentials


approach

Available solutions: Encouraging alignments between vocabularies

http://cultuurlink.beeldengeluid.nl/

Available solutions: An “Entity collection” for Europeana

• As a cornerstone for our strategy we are building an "Entity Collection"• A service that acts as a centralized point of reference

and access to data about contextual entities• Caching and curating data from the wider Linked Open

Data cloud• A sort of Europeana "knowledge graph"



The Entity CollectionUse Cases

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Europeana Collections PortalFindability: users can look for entitiesUnderstandability: Entity Pages group and present all assertions about an entityExploration: Navigation along relationships becomes possible

CrowdsourcingObjects can be annotated with references to entitiesA controlled vocabulary for client applications

Enrichment of Provider’s DataA controlled vocabulary to help identify named references to entities

Republication for Re-useEntities can be republished as an open source to the community



The Entity CollectionDBpedia resource for “Mozart” in our data

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<http://dbpedia.org/resource/Wolfgang_Amadeus_Mozart> a <http://www.europeana.eu/schemas/edm/Agent> ; skos:prefLabel " वोल्फ़गांक आमडेयुस मोत्सार्ट�"@hi, "Волфганг Амадеус Моцарт"@sr, "Волфганг Амадеус Моцарт"@mk, "Волфганг Амадеус Моцарт"@bg; skos:altLabel "Mozart, Johann Chrysostom Wolfgang Amadeus"@en, "Mozart, Wolfgang Amadeus"@en ; dc:identifier "32197206" ; rdaGr2:placeOfBirth <http://dbpedia.org/resource/Austria>, <http://dbpedia.org/resource/Salzburg> ; rdaGr2:placeOfDeath <http://dbpedia.org/resource/Vienna>, <http://dbpedia.org/resource/Austria> ; edm:end "1791-12-05" ; rdaGr2:dateOfDeath "1791-12-05" ; rdaGr2:dateOfBirth "1756-01-27" ; rdaGr2:biographicalInformation … ; owl:sameAs <http://en.dbpedia.org/resource/Wolfgang_Amadeus_Mozart>, <http://zitgist.com/music/artist/b972f589-fb0e-474e-b64a-803b0364fa75>,<http://wikidata.org/entity/Q254>, <http://www4.wiwiss.fu-berlin.de/gutendata/resource/people/Mozart_Wolfgang_Amadeus_1756-1791>, <http://sw.cyc.com/concept/Mx4rvlD9e5wpEbGdrcN5Y29ycA>, <http://yago-knowledge.org/resource/Wolfgang_Amadeus_Mozart>, <http://wikidata.dbpedia.org/resource/Q254>, <http://rdf.freebase.com/ns/m.082db> … .

Preferred labels for 48 languages

Coreference links to 6 other datasets

(e.g. Freebase, Wikidata)

Inter-linking information



Next steps • Generate Europeana URIs for Entities• Make entity services and data available via an API, and

further integrate existing components• Integrate vocabularies that can further enrich the

Collection• Integrate alignments

• particularly, links between local/domain vocabularies to pivot vocabularies

Building a framework for semantic cultural heritage dataEuropeana EssentialsCC BY-SACC BY-SA


28 April 2016

With input slides from Antoine Isaac & Hugo Manguinhas,Europeana R&D team

[email protected]

Technology

Linked Data for EuropeanaCultural Heritage: the Europeana approach