Fall 2019 Entity Resolution in the Web of Data Vassilis Christophides christop@csd.uoc.gr http://www.csd.uoc.gr/~hy562 University of Crete, Fall 2019 Fall 2019 Describing and Linking Entities: Entity-Centric Applications & Knowledge Bases 1 Why “Entities” Fall 2019 2 Fall 2019 Why “Entities” 3 2 “Entities” is What a Large Part of Our Knowledge is About Fall 2019 Bilbao photos Bilbao map One single Entity Pane can answer many user queries and satisfy users’ diverse information needs Weather in Bilbao Time in Bilbao Bilbao Population Popular schools in Bilbao Bilbao places to go 4 Fall 2019 Push/Pull Techniques for Web Content Keyword search Recommendations Personalized search User Intent Augmented search Domain-aware matching Semantic search  https://www.youtube.com/watch?v=L9CPOltkcJA 5 3 Core Entities Fall 2019 Organizations Locations Movies Persons 6 Fall 2019 What Is A Knowledge Base (KB)? dbpedia:Stanley_Kubrick dbo:birt hPlace dbpedia:Manhattan rdf:type foaf:Person rdf:type yago:AmericanFilm Directors rdf:type yago:Amateur ChessPlayers dbpedia: A_Clockwork_Orange_(film) dbo:director dbpedia:Stanley _Kubrick dbo:Work/ runtime “136” foaf:name “A Clockwork Orange” relationships  Comprehensive, machine-readable descriptions of real-world entities are hosted in knowledge bases (KB) Entity names, types, attributes, relationships, provenance info  Entities are described as instances of one or several conceptual types and may be linked through relationships The core Semantic Web data model facts 7 4 Fall 2019 Knowledge Bases: Scope  Domain-specific Knowledge Base Focus is on a well-defined domain: IMDB for movies, Music-Brainz for music, GeoNames for geo, CIA World Factbook for demographics, etc. Global KBs Domain-specific KBs  Global Knowledge Base Covers a variety of knowledge across domains Concept-intensive (Intensional): Cyc, WordNet Entity-intensive (Extensional): DBPedia, Yago, Fr