On 19.08.2014 13:34, David Cuenca wrote:
Markus, is this related with the idea of creating a database of automatically inferred statements that you presented some time ago?
I guess it is related, yes. Although currently I am first focussing on efficient query answering -- inference will come after that :-) Whether one stores the results in a database or not is an implementation detail, btw., that is maybe not essential for a user.
Oh, and of course all of this seems to be rather off-topic for the current subject "Commons Wikibase" :-) All that is relevant there has already been said I guess ("many categories could be expressed by queries to improve results; a gentle, community-led transition will be possible and preferred; categories won't be switched off just because Wikidata is switched on").
Cheers, Markus
Cheers, Micru On Tue, Aug 19, 2014 at 12:30 PM, Markus Krötzsch <mar...@semantic-mediawiki.org <mailto:mar...@semantic-mediawiki.org>> wrote: On 19.08.2014 12:20, Gerard Meijssen wrote: Hoi, I cannot parse this .. What Thomas is saying is that classification (putting things into "categories") and querying (finding things based on certain properties) can be combined in a natural way. In ontology languages like OWL, you can make statements that say, roughly speaking, that "all results of query A belong to class B". This allows you to build a classification partly automatically, and to ensure that your classification is always consistent with your data. >From this perspective, you can view Wikidata's stored queries as similar to OWL's class expressions in that they allow you to define classes based on the data given for each item, without having to go through all the items to add classes manually. What Thomas is referring to is of course slightly more advanced still, but maybe this clarifies part of the idea. Cheers, Markus On 19 August 2014 11:43, Thomas Douillard <thomas.douill...@gmail.com <mailto:thomas.douill...@gmail.com> <mailto:thomas.douillard@__gmail.com <mailto:thomas.douill...@gmail.com>>> wrote: Note that in Wikidata we are developping methods and tools to class items in « classes », which in short are sets of real world things or events. In languages like the w3c language and standards OWL2 <https://en.wikipedia.org/__wiki/OWL2 <https://en.wikipedia.org/wiki/OWL2>>. In this language you can assign a class to an element (a media in the common case) to a class (that can be seen as a better defined category) either by creating a statement « this media belongs to that category » (in Wikidata this is done by using the « instance of » property <https://www.wikidata.org/__wiki/Property:P31 <https://www.wikidata.org/wiki/Property:P31>>) or by associating a so called «class expression» in OWL (an analog of a query but more powerful) Then in OWL any item who satisfy the criteria of the query or class expression associated to a class belongs to that class without stating it explicitely. In short, the possibility to assign an arbitrary class to an item when a query is not enough will also be possible with just a metadata repository, we may in the future even be able to mix these two ways to class medias. 2014-08-19 10:14 GMT+02:00 James Heald <j.he...@ucl.ac.uk <mailto:j.he...@ucl.ac.uk> <mailto:j.he...@ucl.ac.uk <mailto:j.he...@ucl.ac.uk>>>: Also there might be queries one might want to run on the categories, which would be another reason to include them in Commons Wikibase. -- J. On 19/08/2014 07:00, Gerard Meijssen wrote: Hoi, I know the categories in Commons exist. I also know that you do not have to add categories when an image is uploaded. Many people do not consider the categories because they are just there and are not easy nor obvious without a long study. They are there and they evolve. When the "community" finds that they are no longer useful, there will be others who still want to work on it. They can, it is a harmless occupation. Why would we consider removing category structures as long as someone cares about them ?? Thanks, GerardM ___________________________________________________ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org <mailto:Wikidata-l@lists.wikimedia.org> <mailto:Wikidata-l@lists.__wikimedia.org <mailto:Wikidata-l@lists.wikimedia.org>> https://lists.wikimedia.org/____mailman/listinfo/wikidata-l <https://lists.wikimedia.org/__mailman/listinfo/wikidata-l> <https://lists.wikimedia.org/__mailman/listinfo/wikidata-l <https://lists.wikimedia.org/mailman/listinfo/wikidata-l>> _________________________________________________ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org <mailto:Wikidata-l@lists.wikimedia.org> <mailto:Wikidata-l@lists.__wikimedia.org <mailto:Wikidata-l@lists.wikimedia.org>> https://lists.wikimedia.org/__mailman/listinfo/wikidata-l <https://lists.wikimedia.org/mailman/listinfo/wikidata-l> _________________________________________________ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org <mailto:Wikidata-l@lists.wikimedia.org> https://lists.wikimedia.org/__mailman/listinfo/wikidata-l <https://lists.wikimedia.org/mailman/listinfo/wikidata-l> _________________________________________________ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org <mailto:Wikidata-l@lists.wikimedia.org> https://lists.wikimedia.org/__mailman/listinfo/wikidata-l <https://lists.wikimedia.org/mailman/listinfo/wikidata-l> -- Etiamsi omnes, ego non _______________________________________________ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l
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