The DBpedia Dataset

The DBpedia dataset is a large multi-domain ontology which has been derived from Wikipedia. The DBpedia dataset currently describes 2.18 million “things” with 218 million “facts” (February 2008).

1. Background

Wikipedia has grown into one on the central knowledge sources of mankind and is maintained by thousands of contributors.

Wikipedia articles consist mostly of free text, but also contain different types of structured information, such as infobox templates,categorisation information, images, geo-coordinates and links to external Web pages.

For instance, the figure below shows the source code and the visualisation of a infobox template containing structured information about the town of Innsbruck.

This structured information can be extracted from Wikipedia and can serve as a basis for enabling sophisticated queries against Wikipedia content.

The DBpedia.org project uses the Resource Description Framework (RDF) as a flexible data model for representing extracted information and for publishing it on the Web. We use the SPARQL query language to query this data. Please refer to the Developers Guide to Semantic Web Toolkits to find a development toolkit in your preferred programming language to process DBpedia data.

2. Content of the DBpedia Dataset

The DBpedia dataset currently consists of around 218 million RDF triples, which have been extracted from the English, German, French, Spanish, Italian, Portuguese, Polish, Swedish, Dutch, Japanese, Chinese, Russian, Finnish and Norwegian versions of Wikipedia.

The DBpedia dataset describes 2,180,000 “things”, including at least including at least 80,000 persons, 293,000 places, 62,000 music albums, 36,000 films. It contains 489,000 links to images, 2,700,000 links to relevant external web pages, 2,101,000 external links into other RDF datasets, 207,000 Wikipedia categories and 75,000 YAGO categories.

The table below contains links to some example “things” from the dataset:

Class	Examples
City	Cambridge, Berlin, Manchester
Country	Spain, Iceland, South Korea
Politician	George W. Bush, Nicolas Sarkozy, Angela Merkel
Musician	AC/DC, Diana Ross, Röyksopp
Music album	Led Zeppelin III, Like a Virgin, Thriller
Director	Woody Allen, Oliver Stone, Takashi Miike
Film	Pulp Fiction, Hysterical Blindness, Breakfast at Tiffany's
Book	The Lord of the Rings, The Adventures of Tom Sawyer, The holy Bible
Computer Game	Tetris, World of Warcraft, Sam & Max hit the Road
Technical Standard	HTML, RDF, URI

You can also use Richard Cyganiak's PHP script to view random things from the DBpedia dataset.

3. Identifying “things”

Each of the 2.18 million resources described in the DBpedia dataset is identifed by a URI reference of the form http://dbpedia.org/resource/Name, where Name is taken from the URL of the source Wikipedia article, which has the form http://en.wikipedia.org/wiki/Name. Thus, each resource is tied directly to an English-language Wikipedia article.

4. Describing “things”

Each DBpedia resource is described by various properties. Below, we give an overview about the most important types of properties.

4.1. Basic Information

Every DBpedia resource is described by a label, a short and long English abstract, a link to the corresponding Wikipedia page and a link to an image depicting the thing (if availiable).

If a thing exists in multiple language versions of Wikipedia, then short and long abstracts within these languages and links to the different language Wikipedia pages are added to the description. The DBpedia dataset contains the following number of abstracts per language:

4.2. Classifications

DBpedia provides three different classification schemata for things.

1. Wikipedia Categories which are represented using the SKOS vocabulary.
2. The YAGO Classification which is derived from the Wikipedia category system using Word Net. Please refer to Yago: A Core of Semantic Knowledge – Unifying WordNet and Wikipedia for more details.
3. Word Net Synset Links These links were generated by manually relating Wikipedia infobox templates and Word Net synsets and adding a corresponding link to each thing that uses a specific template. In theory, this classification should be more precise then the Wikipedia category system.

Using the classifications within SPARQL queries allows you to select things of a certain type.
Wikipedia Categories:

• NBA Teams (Does not work with Internet Explorer)
• Car manufacturers

YAGO Classes:

• Capitals
• Birds

Wordnet:

• Software
• Airlines

4.3. Infobox Data

The DBpedia dataset contains 22.8 million pieces of information that have been extracted from infoboxes within the English version of Wikipedia. The types of the infobox properties depend on the type of the infobox and there are approximately 8000 different property types. Many infobox property values are typed using XML datatypes.

The infobox data enables sophisticated, fine-grained queries over the dataset. Some example queries are shown below:

• Abstract of movies starring Tom Cruise, released before 1999
• The official website of companies with more than 50000 employees
• Cities with more than 2 million habitants

4.4. External Links

The DBpedia dataset contains HTML links to external webpages as well as RDF links into external data sources.

There are two types of links to HTML pages: dbpedia:reference links point to several web pages about a thing. In addtition, some things also have additional foaf:homepage links that point to webpages that can be considered the “official homepage” of a thing.

RDF links are represented using the owl:sameAs property. Please refer to Interlinking for more information about RDF links and the interlinked datasets.

FOAF Homepage:

• Official websites of Universities
• Official websites of Capitals

Owl:sameAs Links

• Geographical (to geonames.org, eurostat data and the RDF version of the CIA Factbook, both served at the FU Berlin):
  • Countries

• Authors / Books (to quotationsbook.com and Project Gutenberg RDF, served at the FU Berlin. Links to the RDF Book Mashup will follow soon ):
  • Authors

• Computer Scientist publications DBLP, served at the FU Berlin:
  • DBLP

• U.S. Census Statistical Data rdfabout.com, RDF version by Joshua Tauber:
  • Links for U.S. States

4.5. Geo-Coordinates

The DBpedia dataset contains geo-coordinates for 293,000 geographic locations. Geo-coordinates are expressed using the W3C Basic Geo Vocabulary.

Besides simple listings of geo-coordinates (e.g. German soccer stadiums ), the new geo-coordinates allow sophisticated queries, like “show me all things next to the”:

• Eiffel Tower
• Brandenburg Gate

5. License

The DBpedia dataset is licensed under the terms of GNU Free Documentation License.

This material is Open Knowledge.