Accessing the DBpedia Data Set over the Web
The DBpedia data set can be accessed online via a SPARQL query endpoint and as Linked Data.
1. Querying DBpedia
The DBpedia data set enables quite astonishing query answering possibilities against Wikipedia data.
1.1. Public SPARQL Endpoint
There is a public SPARQL endpoint over the DBpedia data set at
http://DBpedia.org/sparql. The endpoint is provided using
OpenLink Virtuoso as back-end database engine.
Please note that not all DBpedia data sets are loaded into the SPARQL endpoint. Especially, only the English infobox data set is loaded and the infobox data sets from other languages are not loaded in order to avoid confusion. For a list of all DBpedia data sets that are loaded into the SPARQL please refer to DatasetsLoaded.
You can ask queries against DBpedia using:
- The Leipzig query builder at
http://wikipedia.3ba.se/
- The OpenLink Interactive SPARQL Query Builder (iSPARQL) at
http://demo.openlinksw.com/isparql
- SNORQL query explorer at
http://DBpedia.org/snorql (does not work with Internet Explorer)
- or any other SPARQL aware client(s).
1.2. Public Faceted Web Service Interface
There is a public Faceted web service over the DBpedia data set at
http://DBpedia.org/fct/service and a Faceted Browser search and find user interface at
http://DBpedia.org/fct. Usage details can be found in the
Virtuoso Facets Web Service documentation.
1.3. Example queries displayed with the Berlin SNORQL query explorer
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People who were born in Berlin before 1900
-
German musicians with German and English descriptions
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German musicians who were born in Berlin
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French films
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First-person shooter computer games
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Luxury cars
1.4. Examples rendering DBpedia Data with Google Map
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Capitals in Europe (in French)
1.5. Example displaying DBpedia Data with Exhibit
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Persons by birthplace (in French, does not work with Internet Explorer)
1.6. Example displaying DBpedia Data with gFacet
gFacet is a new approach for browsing RDF data, which combines graph based visualization and faceted filtering techniques. A demo for DBpedia is available online:
http://www.gfacet.org/dbpedia/
2. Linked Data
Linked Data is a method of publishing RDF data on the Web and of interlinking data between different data sources.
2.1. Background
Linked Data on the Web can be accessed using Semantic Web browsers, just as the traditional Web of documents is accessed using HTML browsers. However, instead of following links between HTML pages, Semantic Web browsers enable users to navigate between different data sources by following RDF links. This allows the user to start off at one data source, and then move through a potentially endless Web of data sources connected by RDF links. It also allows the robots of Semantic Web search engines to follow these links to crawl the Semantic Web.
Please see to Tim Berners-Lee's
Web Design Note about Linked Data and the tutorial on
How to publish Linked Data on the Web for more information about Linked Data.
2.2. The DBpedia Linked Data Interface
The DBpedia data set is served as Linked Data, meaning that all DBpedia URIs are dereferenceable.
This allows you to browse the DBpedia data set with Semantic Web browsers like
DISCO, Marbles,
Objectviewer (site appears to be broken, as of 2008–11–13), the
OpenLink Data Explorer,
Tabulator, or the
Zitgist Data Viewer.
2.3. Sample Resources
Some example Linked Data URIs from the DBpedia data set are listed below. To start surfing the Semantic Web, please enter any of these URIs into the navigation bar of one of the Semantic Web browsers listed above.
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http://dbpedia.org/resource/The_Lord_of_the_Rings
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http://dbpedia.org/resource/Berlin
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http://dbpedia.org/category/Category:Cities_in_England
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http://dbpedia.org/resource/The_Beatles
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http://dbpedia.org/resource/Paul_McCartney
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http://dbpedia.org/category/Category:English_musicians
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http://dbpedia.org/resource/Semantic_Web
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http://dbpedia.org/resource/Tetris
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http://dbpedia.org/resource/Semantic_Web
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http://dbpedia.org/resource/SPARQL
2.4. Sample Views of 2 Sample DBpedia Resources
| Resource | in DISCO | in Marbles | in OpenLink Data Explorer | in Tabulator | in Zitgist Data Viewer |
| | | | | | |
| | | | | | |
3. Semantic Web Crawling Sitemap
Semantic Web Crawling: a Sitemap Extension defines an extension for the Sitemap protocol targeted at the efficient discovery and use of RDF data. Data publishers can state where RDF is located and provide alternative means to access it. Semantic Web clients and Semantic Web crawlers can use this information to access required RDF data in the most efficient way for the task they have to perform.
The Dbpedia project supports this sitemap extension. The DBpedia sitemap, pointing at the SPARQL endpoint, the downloads, and some example instances, is found
here.
Information
Last Modification:
2009-11-05 20:30:38 by Ted Thibodeau Jr
