Monthly Archives: September 2014

DBpedia Version 2014 released

Hi all,

we are happy to announce the release of DBpedia 2014.

The most important improvements of the new release compared to DBpedia 3.9 are:

1. the new release is based on updated Wikipedia dumps dating from April / May 2014 (the 3.9 release was based on dumps from March / April 2013), leading to an overall increase of the number of things described in the English edition from 4.26 to 4.58 million things.

2. the DBpedia ontology is enlarged and the number of infobox to ontology mappings has risen, leading to richer and cleaner data.

The English version of the DBpedia knowledge base currently describes 4.58 million things, out of which 4.22 million are classified in a consistent ontology (http://wiki.dbpedia.org/Ontology2014), including 1,445,000 persons, 735,000 places (including 478,000 populated places), 411,000 creative works (including 123,000 music albums, 87,000 films and 19,000 video games), 241,000 organizations (including 58,000 companies and 49,000 educational institutions), 251,000 species and 6,000 diseases.

We provide localized versions of DBpedia in 125 languages. All these versions together describe 38.3 million things, out of which 23.8 million are localized descriptions of things that also exist in the English version of DBpedia. The full DBpedia data set features 38 million labels and abstracts in 125 different languages, 25.2 million links to images and 29.8 million links to external web pages; 80.9 million links to Wikipedia categories, and 41.2 million links to YAGO categories. DBpedia is connected with other Linked Datasets by around 50 million RDF links.

Altogether the DBpedia 2014 release consists of 3 billion pieces of information (RDF triples) out of which 580 million were extracted from the English edition of Wikipedia, 2.46 billion were extracted from other language editions.

Detailed statistics about the DBpedia data sets in 28 popular languages are provided at Dataset Statistics page (http://wiki.dbpedia.org/Datasets2014/DatasetStatistics).

The main changes between DBpedia 3.9 and 2014 are described below. For additional, more detailed information please refer to the DBpedia Change Log (http://wiki.dbpedia.org/Changelog).

 1. Enlarged Ontology

The DBpedia community added new classes and properties to the DBpedia ontology via the mappings wiki. The DBpedia 2014 ontology encompasses

  • 685  classes (DBpedia 3.9: 529)
  • 1,079 object properties (DBpedia 3.9: 927)
  • 1,600 datatype properties (DBpedia 3.9: 1,290)
  • 116 specialized datatype properties (DBpedia 3.9: 116)
  • 47 owl:equivalentClass and 35 owl:equivalentProperty mappings to http://schema.org

2. Additional Infobox to Ontology Mappings

The editors community of the mappings wiki also defined many new mappings from Wikipedia templates to DBpedia classes. For the DBpedia 2014 extraction, we used 4,339 mappings (DBpedia 3.9: 3,177 mappings), which are distributed as follows over the languages covered in the release.

  • English: 586 mappings
  • Dutch: 469 mappings
  • Serbian: 450 mappings
  • Polish: 383 mappings
  • German: 295 mappings
  • Greek: 281 mappings
  • French: 221 mappings
  • Portuguese: 211 mappings
  • Slovenian: 170 mappings
  • Korean: 148 mappings
  • Spanish: 137 mappings
  • Italian: 125 mappings
  • Belarusian: 125 mappings
  • Hungarian: 111 mappings
  • Turkish: 91 mappings
  • Japanese: 81 mappings
  • Czech: 66 mappings
  • Bulgarian: 61 mappings
  • Indonesian: 59 mappings
  • Catalan: 52 mappings
  • Arabic: 52 mappings
  • Russian: 48 mappings
  • Basque: 37 mappings
  • Croatian: 36 mappings
  • Irish: 17 mappings
  • Wiki-Commons: 12 mappings
  • Welsh: 7 mappings
  • Bengali: 6 mappings
  • Slovak: 2 Mappings

3. Extended Type System to cover Articles without Infobox

 Until the DBpedia 3.8 release, a concept was only assigned a type (like person or place) if the corresponding Wikipedia article contains an infobox indicating this type. Starting from the 3.9 release, we provide type statements for articles without infobox that are inferred based on the link structure within the DBpedia knowledge base using the algorithm described in Paulheim/Bizer 2014 (http://www.heikopaulheim.com/documents/ijswis_2014.pdf). For the new release, an improved version of the algorithm was run to produce type information for 400,000 things that were formerly not typed. A similar algorithm (presented in the same paper) was used to identify and remove potentially wrong statements from the knowledge base.

 4. New and updated RDF Links into External Data Sources

 We updated the following RDF link sets pointing at other Linked Data sources: Freebase, Wikidata, Geonames and GADM. For an overview about all data sets that are interlinked from DBpedia please refer to http://wiki.dbpedia.org/Interlinking.

Accessing the DBpedia 2014 Release 

 You can download the new DBpedia datasets in RDF format from http://wiki.dbpedia.org/Downloads.
In addition, we provide 
some of the core DBpedia data also in tabular form (CSV and JSON formats) at http://wiki.dbpedia.org/DBpediaAsTables.

 As usual, the new dataset is also available as Linked Data and via the DBpedia SPARQL endpoint at http://dbpedia.org/sparql.

Credits

 Lots of thanks to

  1. Daniel Fleischhacker (University of Mannheim) and Volha Bryl (University of Mannheim) for improving the DBpedia extraction framework, for extracting the DBpedia 2014 data sets for all 125 languages, for generating the updated RDF links to external data sets, and for generating the statistics about the new release.
  2. All editors that contributed to the DBpedia ontology mappings via the Mappings Wiki.
  3.  The whole DBpedia Internationalization Committee for pushing the DBpedia internationalization forward.
  4. Dimitris Kontokostas (University of Leipzig) for improving the DBpedia extraction framework and loading the new release onto the DBpedia download server in Leipzig.
  5. Heiko Paulheim (University of Mannheim) for re-running his algorithm to generate additional type statements for formerly untyped resources and identify and removed wrong statements.
  6. Petar Ristoski (University of Mannheim) for generating the updated links pointing at the GADM database of Global Administrative Areas. Petar will also generate an updated release of DBpedia as Tables soon.
  7. Aldo Gangemi (LIPN University, France & ISTC-CNR, Italy) for providing the links from DOLCE to DBpedia ontology.
  8.  Kingsley Idehen, Patrick van Kleef, and Mitko Iliev (all OpenLink Software) for loading the new data set into the Virtuoso instance that serves the Linked Data view and SPARQL endpoint.
  9.  OpenLink Software (http://www.openlinksw.com/) altogether for providing the server infrastructure for DBpedia.
  10. Michael Moore (University of Waterloo, as an intern at the University of Mannheim) for implementing the anchor text extractor and and contribution to the statistics scripts.
  11. Ali Ismayilov (University of Bonn) for implementing Wikidata extraction, on which the interlanguage link generation was based.
  12. Gaurav Vaidya (University of Colorado Boulder) for implementing and running Wikimedia Commons extraction.
  13. Andrea Di Menna, Jona Christopher Sahnwaldt, Julien Cojan, Julien Plu, Nilesh Chakraborty and others who contributed improvements to the DBpedia extraction framework via the source code repository on GitHub.
  14.  All GSoC mentors and students for working directly or indirectly on this release: https://github.com/dbpedia/extraction-framework/graphs/contributors

 The work on the DBpedia 2014 release was financially supported by the European Commission through the project LOD2 – Creating Knowledge out of Linked Data (http://lod2.eu/).

More information about DBpedia is found at http://dbpedia.org/About as well as in the new overview article about the project available at  http://wiki.dbpedia.org/Publications.

Have fun with the new DBpedia 2014 release!

Cheers,

Daniel Fleischhacker, Volha Bryl, and Christian Bizer