On 27.03.2017 15:13, Kingsley Idehen wrote:
On 3/18/17 6:15 PM, Daniel Kinzler wrote:
...
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.
Kingsley,
Wikidata is not a collection of reified RDF statements, but it can
partially be captured by such a collection. There are many ways of
doing this; see [1] for a comparison of some of the more prominent
approaches. All of these encodings can "capture" Wikidata in some way,
but they are not equivalent in terms of RDF or SPARQL. It would
therefore be wrong to claim that any of these possible encodings "is"
Wikidata.
Different RDF encodings are not only non-equivalent but also behave
very differently in practice. Some queries that work well for one
model are very slow or outright impossible to express in another model
[1]. One can therefore not say that the encoding is just a detail and
that Wikidata somehow "in principle" is RDF anyway.
This said, the current Wikidata RDF export should serve the needs of
most people who want to work with an RDF toolchain while having access
to most Wikidata content. One cannot get all details from this
projection, but one can do most practically useful things.
Regards,
Markus
[1] Daniel Hernández, Aidan Hogan, Markus Krötzsch
Reifying RDF: What Works Well With Wikidata?
In Thorsten Liebig and Achille Fokoue, eds., Proceedings of the 11th
International Workshop on Scalable Semantic Web Knowledge Base
Systems, volume 1457 of CEUR Workshop Proceedings, 32-47, 2015.
CEUR-WS.org
https://iccl.inf.tu-dresden.de/web/Inproceedings3037
Markus,
Let's agree to disagree, for now :)
--
Regards,
Kingsley Idehen
Founder & CEO
OpenLink Software (Home Page: