Am 27.03.2017 um 15:13 schrieb Kingsley Idehen:
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.
It's a matter of perspective.
I agree that Wikidata can be *represented* as a collection of reified RDF
Statements. That's what we do for the query service. But I do not agree that
this is what Wikidata *is*.
RDF and the Wikibase model are quite different conceptually. But they are of
equal power and thus formally equivalent: one can be represented using the
other. Just because a Turing Machine is computationally equivalent to lambda
calculus, that does not mean they are the same thing. Understanding one in terms
of the other may be helpful in some context, and irrelevant in another.
There is nothing special about the relationship between Wikibase/Wikidata and
RDF; Wikibase has an RDF binding, but it is not defined in terms of RDF, its
specification does not rely on RDF concepts. The Wikibase model can just as well
(or perhaps more easily) be understood and represented in terms of the Topic
Maps model (ISO 13250).
Academically, the Wikibase model could perhaps be described as an extended model
logic with reasoning rules for provenance. I think W. Stelzner explored related
ideas in the 80s. Maybe one day I'll find the time to dig into this some more.
--
Daniel Kinzler
Principal Platform Engineer
Wikimedia Deutschland
Gesellschaft zur Förderung Freien Wissens e.V.