If I may chime in: Most, if not all, of the (overly specific) categories on Commons can be expressed by statements. So, storing the data/time from EXIF or otherwise would allow for a "midsummer morning" query. Adding EXIF camera model to the file data item would allow to query for cellphones (it would probably reference the cellphone model item on Wikidata, which in turn is an instance of cell phone).

This can be done with live queries a la WDQ, or stored procedures a la "complex queries" which are planned for Wikidata, as a click-on category replacement, if such a thing is desired.

Cheers,
Magnus


On Mon, Aug 18, 2014 at 3:22 PM, James Heald <j.heald@ucl.ac.uk> wrote:
Thanks Lydia!

Something that occurs to me is that one may well want to include Commons categories in such a database, not just files, which presumably might be stored on a page like

  Info:Category:Insert random Commons category intersection here

so that one could then ask whether a file belongs to such a category or not, and the data would all be in the database.


Such categories (or sets) may well not be Wikidata notable, for example:

  Category:Pictures I took on my cellphone one midsummer morning

so we cannot assume they have Q-numbers.


But it would be nice if we could describe such properties using the existing Wikidata syntax, ie via a property Pxyz = "belongs to set", and then an item number for the set it belonged to.

Since the items wouldn't be on Wikidata, it would be useful if they had a different namespace,  eg   C nnnnnn

Of course some of the categories would be on Wikidata,  so for such categories one would want to create a tie between the item on Commons Wikibase and the item on Wikidata,

   C nnnnn <--> Q mmmmm

Sorry if I'm being premature and getting ahead of things, but this is the sort of thing I had in the back of my mind.


On the other hand I can quite see if, to start with, you want only to have files as items on Commons WikiBase  (CWB ?).   But even then, it's quite nice to have an Wikidata-style identifier syntax for talking about them,  eg  C nnnnn  again.


(I'm not particularly hung up about the "C" -- it could be anything. But "F" for file is perhaps potentially too restrictive for future development).

Just typing out of the top of my head here,

Best,

   James.



On 18/08/2014 14:30, Lydia Pintscher wrote:
Hey James :)

On Sat, Aug 16, 2014 at 9:56 PM, James Heald <j.heald@ucl.ac.uk> wrote:
Out of interest, are there any thoughts as to how templates are likely to
access Commons Wikibase ?

I could image Commons Wikibase sharing the same Properties (Pxxx) but having
its own items -- perhaps starting C (Cnnnn).

Such a structure would make it easy to prototype templates using items on
Wikidata while Commons Wikibase was being developed, just changing the
relevant Q-numbers to C-numbers to port from accessing an item defined on
Wikidata to one defined on Commons Wikibase.

Properties on C-numbers could point to Q-numbers; but (with very rare
exceptions) properties on Q-numbers would not point to C-numbers.

Is that likely to be how things will be set up?

I'm not sure we're talking about the exact same thing so let me write
down how I envision it:

* For a file on Commons there will be a second page on Commons that
holds the structured data about that file. So if the file is
HamsterBerta.jpg then we have something like Info:HamsterBerta.jpg.
(Info isn't decided yet!) This is what we currently call MediaInfo and
is comparable to an item on Wikidata.
* On Info:HamsterBerta.jpg we have statements like "topic:hamster" and
"license:CC-BY-SA". topic, hamster, license and CC-BY-SA would be
linked to Wikidata properties and items respectively.
* This data can then be accessed on File:HamsterBerta to make it look
roughly like today if people want that. One option would be to take
the Information template and rewrite it so that it takes data from the
MediaInfo page where avaiable.

Does that make it a bit more clear? I should make a graphic from this...


Cheers
Lydia



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