Linked open data

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Linked Open Data ( LOD ) refers to freely available data on the World Wide Web that is identified by Uniform Resource Identifier (URI) and can be accessed directly via HTTP and also refer to other data via URI. Ideally, the Resource Description Framework (RDF) and standards based on it such as the query language SPARQL and the Web Ontology Language (OWL) are used to code and link the data so that their meaning can be correctly interpreted by machines. Thus Linked Open Data is part of the Semantic Web . The linked data result in a global network, which is also known as a "Linked [Open] Data Cloud" or "Giant Global Graph". Where the focus is less on the free usability of data than with free content ( open data ), the term linked data is also common.

Idea of ​​open networked data

Open networked data are all data stocks that are made freely accessible in the interest of the general public of society without any restriction for free use, dissemination and further use and are networked with one another via the World Wide Web.

Basic concept

While the WWW is a network of websites , Linked Open Data is intended to create a network of data that can be automatically reused from various sources ( information integration ). The concept of Linked Open Data essentially goes back to Tim Berners Lee , who also proposed the name “Giant Global Graph” (GGG) at the end of 2007. He coined four rules for linked data:

  1. Use URIs as names for things
  2. Use HTTP URIs so that people can look up those names.
  3. When someone looks up a URI, provide useful information, using the standards (RDF, SPARQL)
  4. Include links to other URIs so that they can discover more things.
  1. Use URIs to label objects.
  2. Use HTTP URIs so that the names can be looked up.
  3. Provide pertinent information when someone looks up a URI (using the RDF and SPARQL standards ).
  4. This information includes, in particular, links to other URIs via which further objects can be discovered.
Linking between Linked Open Data databases (September 2011)

A popular representation of the Linked Open Data Cloud was created in October 2007 and has been updated several times since then. It contains, for example, the databases of DBpedia and GeoNames .

Web links

Individual evidence

  1. ^ Jörn von Lucke, Christian P. Geiger: Open Data Government. Freely available public sector data. (PDF; 500 kB) (No longer available online.) In: Zeppelin University. December 3, 2010, p. 4 , archived from the original on December 14, 2010 ; accessed on June 29, 2019 .
  2. ^ Paul Miller: Who is afraid of the GGG? ( Memento of December 1, 2007 in the Internet Archive ) In: Nodalities Blog, November 26, 2007.
  3. Linked Data - Design Issues. In: , accessed June 29, 2019.
  4. ^ The suffix "using the standards (RDF, SPARQL)" was only introduced later, see version of November 15, 2006 .
  5. Richard Cyganiak, Anja Jentzsch: The Linked Open Data Cloud. October 2007 to September 2011.