Markus, is this related with the idea of creating a database of
automatically inferred statements that you presented some time ago?
Cheers,
Micru
On Tue, Aug 19, 2014 at 12:30 PM, Markus Krötzsch <
markus(a)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.douillard(a)gmail.com
<mailto:thomas.douillard@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>. 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>) 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.heald(a)ucl.ac.uk
<mailto:j.heald@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
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