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![The Entity API - entity look-up/resolving
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• Linked Data content negotiation at data.europeana.eu (for JSON-LD and
HTML)
• API call for JSON-LD via entity identifiers
• https://www.europeana.eu/api/entities/[entity_class]/base/
[ID].jsonld
• resolve method for getting data on an Entity for an external URI (that
appear in sameAs-like equivalence statement)
• https://www.europeana.eu/api/entities/resolve?uri=[URI]
• We created a specific JSON-LD context to make the data easier to
consume for web developers, e.g. hiding RDF namespace abbreviations
Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage](https://image.slidesharecdn.com/isaac-designingamultilingualkg-dcmi18-180912231141/75/Designing-a-multilingual-knowledge-graph-DCMI2018-22-2048.jpg)
Uploaded byAntoine Isaac
Designing a multilingual knowledge graph - DCMI2018
The document discusses the design and implementation of a multilingual knowledge graph as a service for cultural heritage by the Europeana Foundation. It outlines the challenges faced in building this knowledge graph, the strategies for integrating and enriching metadata from various cultural heritage institutions, and the functionalities of the entity collection API. Furthermore, it emphasizes the importance of improving user experience and discoverability of cultural heritage objects through a linked data approach.
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Designing a multilingual knowledge graph - DCMI2018
- 1. Designing a MultilingualKnowledge Graph as a Service for Cultural Heritage Some Challenges and Solutions Valentine Charles, Hugo Manguinhas, Antoine Isaac - Europeana Foundation Nuno Freire - INESC-ID Sergiu Gordea - AIT DCMI Conference 2018
- 2. What is Europeana? CCBY-SA We aggregate metadata: • From all EU countries • ~3,700 galleries, libraries, archives and museums • More than 58M objects • In more than 40 languages • Huge amount of references to places, agents, concepts, time periods Europeana aggregation infrastructure Europeana| CC BY-SA The Platform for Europe’s Digital Cultural Heritage Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage
- 3. Europeana Linked DataStrategy Our lines of work CC BY-SA • The Europeana Data Model (EDM) offers a base for linking metadata • We apply automatic enrichment to link object metadata to reference datasets • We encourage data providers to contribute their own links to vocabularies • We encourage alignment activities between domain vocabularies Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage
- 4. Europeana Linked DataStrategy LOD Vocabularies currently recognized by Europeana in providers' metadata CC BY-SA Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage Vocabulary URL MIMO Concepts http://www.mimo-db.eu/ MIMO Instrument makers http://www.mimo-db.eu/ The Getty - Art & Architecture Thesaurus (AAT) http://vocab.getty.edu/ The Getty - Union List of Artist Names (ULAN) http://vocab.getty.edu/ Virtual International Authority File (VIAF) http://viaf.org/viaf/ Geonames http://sws.geonames.org/ IconClass http://iconclass.org/ Gemeinsame Normdatei (GND) http://d-nb.info/gnd Israel Museum Jerusalem Concepts http://www.imj.org.il/imagine/thesaurus/objects/ Partage Plus concepts http://partage.vocnet.org/ data.europeana.eu WWI Concepts from Library of Congress Subject Headings (LCSH) http://data.europeana.eu/concept/loc Europeana Sounds Genres http://data.europeana.eu/concept/soundgenres/ EAGLE Material & Object Type http://www.eagle-network.eu/voc/ DISMARC Formats & Genres http://purl.org/dismarc/ns/ UDC http://udcdata.info/rdf/ UNESCO Thesaurus http://vocabularies.unesco.org/thesaurus/
- 5. Europeana Linked DataStrategy A strategy for Entities CC BY-SA We are building an "Entity Collection" • A service that acts as a centralized point of reference and access to data about contextual entities: places, agents (persons and organizations), concepts... • Caching and curating data from the wider Linked Open Data cloud • A sort of Europeana "knowledge graph" with an API • A service can be re-used by everyone in our community Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage
- 6. Uses cases forthe Entity Collection (1/2) CC BY-SA Improve user experience on Europeana services ● Findability: users can search with and for people, places and subjects, not only objects. In many more languages, and with less ambiguity ● Contextualization: users see contextual information about cultural heritage objects. Entity Pages group and present all assertions about an entity ● Exploration: Browsing along relationships between objects and entities and between entities Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage Semantic auto- completion Entity Pages Entity based facets Europeana Food & Drink Project
- 7. Uses cases forthe Entity Collection (2/2) CC BY-SA Crowdsourcing ● Objects can be annotated with references to entities of their context Automatic enrichment of providers' metadata ● A controlled vocabulary to help recognize references to entities Republication for Re-use ● Entities can be republished as an open source to the community Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage Semantic and Metadata annotations Pundit Annotation Client from Digital Manuscripts to Euiropeana (DM2E)
- 8. Related work CC BY-SA • Knowledge graph creation and maintenance: Google's Knowledge Graph, DBpedia, Wikidata, BabelNet, VIAF, Entity Facts, SNAC, Europeana Food and Drinks • (Vocabulary) web services: STW, DigitalNZ's Concept API... • W3C's best practices for publishing (linked) data on the Web • Data alignment tools and methods • Semantic discovery services: Worldcat Identities, etc. Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage
- 9. In this presentation CCBY-SA • Challenges, decisions and results for • Building a knowledge graph for Europeana • Accessing it for exploitation • Disclaimers: • The focus is operational, this is not groundbreaking research! Sometimes we will state the obvious... • Europeana's Entity Collection is still work in progress! Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage
- 10. The things we'llbe talking about Entity Collection processes in Europeana CC BY-SA Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage
- 11. Building a knowledgegraph for Europeana France, Public Domain 1914, National Library of France Agence de presse Meurisse Concours de cycles nautiques sur le lac d’Enghien : Berregent piloté par Austerling
- 12. Selecting data sources CCBY-SA An intellectual effort by data experts, leveraging the following criteria: • Availability and access: open license, published on the web as linked data • Granularity and coverage: similar or complementary sets of entities, multilingual data, helping to answer key user needs for Europeana's CH collections. Too generic datasets can create too much ambiguity for the simple processes we have (e.g. enrichment) • Size: larger vocabularies are useful, but sometimes create too much ambiguity • Quality: intrinsic aspects like correctness of representation (data structures) • Connectivity: good data sources are well-connected internally and externally to other datasets An approach based on pivot (e.g. DBpedia, Wikidata) and specialized data sources (e.g. AAT) is likely to work well if links can be made between them Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage
- 13. Statement selection andmappings CC BY-SA Conceptually distinct steps, which may be grouped at implementation time: • Selection of entities within one dataset • E.g. selecting artists (excluding pop stars) from DBpedia • Mappings between model of data source and model of KG • Made easier if both use standards, e.g. SKOS or FOAF - both re-used by the Europeana Data Model • Selection of relevant statements • E.g. filtering unwanted languages larger vocabularies are useful, but sometimes create too much ambiguity Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage
- 14. Example: integrating DBpediaresources CC BY-SA Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage
- 15. Data integration andreconciliation CC BY-SA • Import of entities needs integrating old statements with new ones if entities are redundant recognized to be the same (via available sameAs- like equivalence statements) • Several options for data integration on entities: a. unification: lumping all statements together - possibly leading to inconsistencies or cardinality constraints b. first come, first serve: only adding statements from most recent sources when it's possible, i.e. not violating cardinality constraints c. most representative: possibly replacing old statements by new ones if they come from a "prefered" source d. differentiated most representative: grouping data sources in sets that have different level of preference, so as to apply c between these sets. b and c may be applied within the sets. Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage
- 16. Alignment and curation CCBY-SA • Alignment aims at recognizing more equivalent entities in the data sources to be integrated • It can use automatic or semi-automatic tools like Wikidata Mix'n'Match or CultuurLink, both experimented in Europeana's context • It requires a lot of effort/expertise at the scale we're considering! • Curators should be able to edit data to maintain integrity in the Entity Collection or elsewhere downstream • Removing, editing, adding statements or deprecating entities, e.g. to prevent ambiguities that lead to wrong enrichment of object metadata Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage
- 17. Data currently inthe Entity Collection CC BY-SA Mostly corresponding to a selection made for Europeana's Semantic Enrichment • Places a subset of Geonames, corresponding to places which are part of European countries and of some specific feature classes. • Agents a subset of DBpedia corresponding to most of the instances of dbp:Artist with some exceptions, and integrated from 49 DBpedia language editions. • Concepts a subset of DBpedia corresponding to a selection concepts matching the needs from Europeana Collections (e.g., WWI battles). Europeana Sounds music genres (obtained from Wikidata) Photo Consortium's photography vocabulary • Organizations Extracted from Europeana's CRM and aligned to Wikidata when possible 216,302 resources 1,572 resources 165,005 resources 1,077 resources Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage
- 18. Multilingual coverage ofthe Entity Collection And its contribution to automatic enrichment CC BY-SA Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage Entities effectively used to enrich Europeana Objects Entities present in the Entity Collection https://docs.google.com/document/d/1Nek_SPDtIR3waYwwdgRHY1YiTCj3SK8Eh9xYpnSkFkY
- 19. France, Public Domain 1932,National Library of France Agence de presse Mondial Photo-Presse. Tournoi royal de motos à Londres : changement d'une roue de side-car en marche Accessing and exploiting the data in the Entity Collection
- 20. Entity URIs CC BY-SA • Step 0 for publishing our Linked Data on the web: minting URIs for our entities • It's always a difficult choice between length, ease of persistence, human- friendliness... • We've looked at best practices and consulted our community • Chosen pattern is http://data.europeana.eu/{entity_class}/ {scheme}/{localID} • Where localID is a sequential identifier • For example, the agent Leonardo da Vinci: http://data.europeana.eu/ agent/base/146741 Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage
- 21. The Entity API CCBY-SA • Still on alpha state • Looking at best practices for Linked Data and JSON-LD • Available documentation for this API at: https://pro.europeana.eu/resources/apis/entity Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage
- 22. The Entity API- entity look-up/resolving CC BY-SA • Linked Data content negotiation at data.europeana.eu (for JSON-LD and HTML) • API call for JSON-LD via entity identifiers • https://www.europeana.eu/api/entities/[entity_class]/base/ [ID].jsonld • resolve method for getting data on an Entity for an external URI (that appear in sameAs-like equivalence statement) • https://www.europeana.eu/api/entities/resolve?uri=[URI] • We created a specific JSON-LD context to make the data easier to consume for web developers, e.g. hiding RDF namespace abbreviations Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage
- 23. The Entity Collection DBpediaresource for “Mozart” in our data CC BY-SA Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage Coreference links to 6 other datasets (e.g. Freebase, Wikidata) Inter-linking information… still need to switch references to link to Europeana Entities Preferred labels for 48 languages
- 24. The Entity API- discovery CC BY-SA • Suggestion of entities for a type string, used the auto-complete function in Europeana's search box • https://www.europeana.eu/api/entities/suggest • For example: https://www.europeana.eu/api/entities/suggest? wskey=apidemo&text=leo&type=agent • Ranking of suggestions is based on: • Europeana relevance: number of Europeana objects whose description contains one of the entity's labels • Popularity as computed in the Wikidata pagerank (Diefenbach & Thalhammer, 2018) • Coming soon: general entity search, based on free (Solr-style) querying on metadata fields for entities Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage
- 25. Entity API -suggest method CC BY-SA Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage /entities/suggest.json?text=neo
- 26. Conclusions CC BY-SA • We'vemade enough progress to release a first version of the Entity Collection and its API, used in Europeana's production services. • But there are still challenges and decisions to ensure consistency and relevance over time: • Expand data coverage (and test extensibility) with new data sources for, e.g., events • Continue elaborating and testing data integration and filtration strategies • Employ the EC to better enrich Europeana object metadata • Enhance discoverability, especially for search engines, e.g. via Schema.org publication Designing a Multilingual Knowledge Graph as a Service for Cultural Heritage
- 27.