Interlinking DBpedia with other Data Sets

Linked Data is a method to publish data on the Web and to interlink data between different data sources. Linked Data can be accessed using Semantic Web browsers, just as traditional Web documents are accessed using HTML browsers. However, instead of following document links between HTML pages, Semantic Web browsers enable surfers to navigate between different data sources by following RDF links. RDF links can also be followed by robots or Semantic Web search engines in order to crawl the Semantic Web. See Linked Data – The Story so far and How to publish Linked Data on the Web for more information about Linked Data.

The DBpedia data set is interlinked with various other data sources. The diagram below gives an overview of some of these data sources:

Data Set	Description	Number of Links	Example Link (owl:sameAs)
Geonames	Provides information about geographic features.	85,000	Cambridge
MusicBrainz	Provides information about artists and music.	23,000	Portishead
WordNet	W3C RDF/OWL representation of the Word Net ontology.	330,000	Air France
World Factbook	Provides information about countries.	200	France
EuroStat	Provides information about European countries and regions.	200	France
Book Mashup	Provides information about books.	7,000
DBLP Bibliography	Provides information about scientific publications.	200	Tim Berners-Lee
Project Gutenberg	Provides information about authors and open access to their work.	2,500	John Bunyan
flickr wrappr	A wrapper around flickr that tries to generate a photo collection for each DBpedia concept.	1,950,000	Brandenburg Gate
Freebase	A open-license database about millions of things from various domains.	2,400,000	Tetris
OpenCyc	A open-license version of the Cyc Ontology.	60,000	Woody Allen
UMBEL	A lightweight, subject concept reference structure derived from Cyc.	20,000	Place
US Census	Provides US Census data.	12,000	Los Angeles
Dailymed	Provides information about drug.	50	Eli Lilly and Company
Diseasome	Provides information about diseases and genes.	2000	Asthma
Drugbank	Provides information about drugs and genes.	700	ZNF3
Sider	Provides information about side effects of drugs.	750	Claudication

The W3C Linking Open Data Community Project

DBpedia is part of the W3C Linking Open Data community project, an effort to publish and interlink various open data sources. As of November 2009, this effort has built a Web of interlinked data sources that amounts to more than 6 billion RDF triples. Please refer to the project's data sets page for a list of all published data sets.

Linking to DBpedia from Your FOAF Profile

As Wikipedia contains articles about many general-purpose concepts, DBpedia can also be seen as a huge ontology that assigns URIs to plenty of concepts and backs these URIs with with dereferenceable RDF descriptions.

If you have a FOAF profile and you need terms for describing your interests or your location, you might consider using DBpedia URIs. This will allow RDF browsers like Disco, Tabulator, or the OpenLink Data Web Browser, to browse from your FOAF profile into DBpedia. The links also allow clients like the Semantic Web Client Library to answer SPARQL queries over both data sources.

The example below shows an RDF link from Richard Cyganiak's FOAF profile which states that he is based near Berlin.

<http://richard.cyganiak.de/foaf.rdf#cygri> foaf:based_near <http://DBpedia.org/resource/Berlin>

You can use the Disco browser to follow this link by clicking here.

DBpedia URIs can also be used to express your interests within your FOAF profile. For example:

<http://richard.cyganiak.de/foaf.rdf#cygri> foaf:topic_interest <http://DBpedia.org/resource/Tetris> .
<http://richard.cyganiak.de/foaf.rdf#cygri> foaf:topic_interest <http://DBpedia.org/resource/Semantic_Web> .

Another use case for DBpedia URIs could be to categorize or tag blog posts, wiki pages, or other documents. For example:

<http://news.cnn.com/item1143> dc:subject <http://DBpedia.org/resource/Iraq_War>; 
                               foaf:primaryTopic <http://DBpedia.org/resource/Iraq_War>; 
                               foaf:topic <http://DBpedia.org/resource/Middle_East>;

An interesting project that allows you to review anything that has a URI is the RevYu project run by Tom Heath. A Rev Yu review about a film in DBpedia could look like this:

@prefix rev: <http://purl.org/stuff/rev#> . 
@prefix foaf: <http://xmlns.com/foaf/0.1/> . 
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> . 

<> a rev:Review; 
   rdfs:label "Review of Cold Mountain, by Alice";  
   foaf:primaryTopic <http://DBpedia.org/resource/Cold_Mountain_%28film%29> ; 
   rev:text "This movie sucks. Miss it."; 
   rev:rating 1; 
   rev:minRating 1; 
   rev:maxRating 5; 
   rev:reviewer <http://example.com/alice/foaf.rdf#me> .