Best practices for Linked Data

Transcription

1 Best practices for Linked Data Asunción Gómez-Pérez Facultad de Informática, Universidad Politécnica de Madrid Avda. Montepríncipe s/n, Boadilla del Monte, Madrid Phone: , Fax: Acknowledgements: M. Poveda, V. Rodríguez-Doncel, D. Vila BabeLData: TIN

2 Asunción Gómez-Pérez Spain 2013 Madrid, 18 th December Linked Data: why it is important? Facilitate data integration From heterogeous sources In different formats Different granularity In different languages From different countries Slide adapted from 5min Introduction to Linked Data - Olaf Hartig

3 Asunción Gómez-Pérez Spain 2013 Madrid, 18 th December 3 3 BD BNE BD VIAF BD AEMET BD IGN BD Prisa BD DBpedia Data Integration BNE Ubicado en Alcalá de Henares 1605 El Quijote Año de Publicación Autor birthplace Same as M. Cervantes M. Cervantes Alcalá de Henares M. Cervantes Year of publication creator Don Quixote 1960 Translated into Hebrew VIAF located Alcalá de Henares guía Tapas Siglo de Oro Alcalá de Henares Temperatura 20º

4 RDF(S) models Unique identifiers: URI identify or name a resource Foundations Equivalence links to other datasets Same As Data navigation Person Is creator of Cer Work Is a Is a Cervantes Is creator of Cer El Quijote Same As Same As Cervantes Cervantes Asunción Gómez-Pérez Spain 2013 Madrid, 18 th December 4

5 Asunción Gómez-Pérez Spain 2013 Madrid, 18 th December 5 5 The model (Ontology) and the data for humans Idiom Year translation Publication date Work Is creator of Person birthplace Place Ontology Located at Library Has subject Catalán 1960 translation Publication date El Quijote Is creator of Cervantes birthplace Alcalá de Henares Located in Has subject Vida de Cervantes Data BNE

6 Asunción Gómez-Pérez Spain 2013 Madrid, 18 th December 6 6 The model and the data for Machines Language Ontology translation work Is creator of Person Año Publication date birthplace Located in Has subject Biblioteca Catalán translation de Henares 1960 Publication date Don Quijote de la Mancha Es autor Cervantes Saavedra, Miguel de birthplace Has subject BNE Located in Vida de Miguel de Cervantes Saavedra Data

7 Asunción Gómez-Pérez Spain 2013 Madrid, 18 th December Linked Data is to be processed by machines

8 Asunción Gómez-Pérez Spain 2013 Madrid, 18 th December The generation process Providers Domains Sources Languages

9 The Linked Data Generation Process Specification Data Curation Exploitation Modelling Publication Generation Linking 9 There is no One-Size-Fits-All Formula

10 Lot of data in many domains Music On-line activities E-Gov Cross-domains Publications Geographic Life Sciences

11 I want to use Linked Open Data Who generated the LD dataset? When the LD dataset was created? How the LD dataset was created? Is the latest version of the LD dataset? Is the license information clearly stated in the LD dataset? How is LD licenses offered? Is the LD dataset monolingual or multilingual?

12 LOD observations How the LD generation process influence the use of the data by third parties? Vocabularies Licenses Language Provenance

13 Asunción Gómez-Pérez Spain 2013 Madrid, 18 th December How to prevent GIGO GARBAGE PROCESS

14 Vocabularies 14 th

15 Asunción Gómez-Pérez Spain 2013 Madrid, 18 th December Cervantes at the data level Same as URI URI URI URI URI Cervantes Same as Same as D. Quijote Author Phone Date of Birth #People Same as 1547 Size ,4 km²

16 rdf:type Cervantes and a bit of semantics rdf:type Person Retaurant URI URI URI URI URI Cervantes (Person) rdf:type Same as rdf:type Street Author D. Quijote Date of Birth rdf:type Municipality Asunción Gómez-Pérez Spain 2013 Madrid, 18 th December

17 17 Cervantes foaf foaf:agent foaf:group foaf:organization foaf:document foaf:person foaf:publications foaf:image foaf:mbox - foaf:firstname - foaf:surname - foaf:birthday foaf:img owl:thing foaf:knows foaf:depiction Miguel de Cervantes Saavedra foaf:firstname foaf:surname instanceof bibliothek:cervantes instanceof foaf:homepage instanceof instanceof foaf:birthday foaf:img /images/quixote.tif foaf:publications foaf:depiction

18 18 License Information

19 How Open is the Open Linked Data Cloud? LOD observations: Licenses

20 An example: the British National Bibliography

21 License Information is not up to date

22 Metadata information without license information

23 License information provided as XML

24 Linked Data Rights pattern

25 Lenguage 25

26 Rationale: LOD is dominated by the English Language Questions: 1. Searching resources in a particular language 2. Distribution of natural languages across RDF datasets? 3. Usage of language tags to indicate the natural language of RDF tags? 1. Distribution of usage of language tags 2. Distribution of literals tagged as English vs other languages 3. Distribution of literals tagged in languages other than English 26

27 Asunción Gómez-Pérez Spain 2013 Madrid, 18 th December 27 Example of multilingual library resource The dataset publisher does not tag the language of the content of different fields Ernest Hemingway and El viejo y el mar MARC 21 records

28 Asunción Gómez-Pérez Spain 2013 Madrid, 18 th December Multilingualism and the Linked Data Process How to represent language information for datasets? # VoiD description :bne a void:dataset; dcterms:language < # DCAT description :bne a dcat:dataset; dcterms:language < How to represent language information in Linked Data? Traditional annotation properties for most cases dbpedia:miguel_de_cervantes rdfs:label "Miguel de Cervantes"@es. "ミゲル デ セルバンテス"@ja. " "@ko. Richer models for more demanding applications # LEMON isbd:t1001 lemon:isreferenceof [lemon:issenseof :cartographic]. :cartographic a lemon:lexicalentry; lemon:form [lemon:writtenrep isocat:grammaticalgender isocat:masculine]; lemon:form [lemon:writtenrep isocat:grammaticalgender isocat:feminine]. isocat:grammaticalgender rdfs:subpropertyof lemon:property.

29 Implementation of the recording of data and metadata provenance Generation process Resource provenance DC File.txt creator creadondate John rights GPL used Revision Process generatedby PROVENANCE Model (RDF(S)) Filev1. txt RDF Store 29 1

30 Asuncion Gomez-Perez Spain 2013 Madrid, 18 th December Conclusions The use of Data curated Use vocabularies widely known License metadata in RDF Language metadata in RDF Provenance metadata in RDF Will influence the use of the linked data by third parties

31 Thanks for your attention! Asuncion Gomez-Perez Guidelines for Multilingual Linked Data. WIMS 2013 Madrid, June 31

32 There is no One-Size-Fits-All Formula Phase BNE IGN AEMET PRISA INE Modeling DC hydrontology Wgs84 time SSN ontology SIOC Scovo Data cube RDF generation MARiMbA geometry2rdf NOR2O CSV parser CSV parser NOR2O Links generation DNB VIAF LIBRIS DBPEDIA Silk Silk Silk DBPEDIA DBPEDIA Geolinkeddata.es Geonames Geolinkeddata.es NOR2O Geolinkeddata.es Publication Pubby sitemap4rdf Exploitation map4rdf SPARQL

33 The multilingual Web of Data: Current state Monolingual datasets Multilingual datasets RDF literals without language tag RDF literals with language tag ,567,324 3,154,779 3,365,930 1,906 2,201 1,984 10,250,936 10,594,338 12,272,806 January 2012 June 2012 December Number of Monolingual and multilingual datasets January 2012 June 2012 December Current usage of language tagging capabilities in RDF RDF literals with English tag RDF literals with other language tag 431, , ,785 2,135,664 2,751,065 2,808,145 January 2012 June 2012 December English tags versus other languages' tags 4. Evolution of top-10 languages 33