On 3/18/17 6:15 PM, Daniel Kinzler wrote:
Am 18.03.2017 um 22:48 schrieb Bob DuCharme:
New question: when I see that https://www.wikidata.org/wiki/Special:EntityData says "This page provides a linked data interface to entity values", can you tell me what "entity" means in the context of Wikidata? If I was going to refer to something that can be identified with a URI and described by triples in which it is the subject, I would just use the term "resource" as described at https://www.w3.org/TR/rdf11-concepts/#resources-and-statements (and remembering what "RDF" stands for!) so I'm guessing that "entity" means something a little more specific than that here.
The Wikidata (or technically, Wikibase) data model is not defined in terms of RDF. Have a look at the primer https://www.mediawiki.org/wiki/Wikibase/DataModel/Primer and the spec https://www.mediawiki.org/wiki/Wikibase/DataModel.
Entitites are the top level elements of Wikidata. There are currently two kinds: Items (things or concepts in the world) and Properties (attributes for describing Items and other entities).
Wikibase Entities are certainly Resources in the RDF sense, but so are some of the more fine grained components of the Wikibase model, such as Statements and References. You can find the OWL file for the RDF binding of Wikibase at http://wikiba.se/ontology.
Daniel,
I see Wikidata is a collection of reified RDF Statements. I don't see how this model differs from RDF's model. It just so happens (in my eyes) that Wikidata includes description of statements about things which provides rich metadata, in line with the goals of Wikidata.