3.5 Linked Open Data (LOD)
The Semantic Web is a Web of Data — of dates and titles and part numbers and chemical properties and any other data one might conceive of (W3C103). “Linked Data is simply about using the Web to create typed links between data from different sources. These may be as diverse as databases maintained by two organisations in different geographical locations, or simply heterogeneous systems within one organisation that, historically, have not easily interoperated at the data level. Technically, Linked Data refers to data published on the Web in such a way that it is machine-readable, its meaning is explicitly defined, it is linked to other external data sets, and can in turn be linked to from external data sets” (Bizer, Heath & Berners-Lee, 2009104). W3C describes DBPedia105 as a typical example of a large Linked Dataset, which, essentially, makes the content of Wikipedia available in RDF. The importance of DBPedia is not only that it includes Wikipedia data, but also that it incorporates links toother datasets on the Web, e.g., to Geonames106. By providing those extra links (in terms of RDF triples) applications may exploit the extra (and possibly more precise) knowledge from other datasets when developing an application; by virtue of integrating facts from several datasets, the application may provide a much better user experience.