On Wed, Dec 3, 2008 at 11:05 AM, Roan Kattouw <roan.kattouw(a)home.nl> wrote:
Without addressing Commons in particular, having an
efficient way to get
pages in the intersection of multiple categories would allow wikis to
delete a category such as [[Category:Deceased Presidents of the United
States]] and replace it by, say, [[Intersection:Deceased Presidents of
the United States]], which would list all articles in
[[Category:Deceased people]] and [[Category:Presidents of the United
States]]. My extension alone doesn't make that possible, but it makes
implementing such a feature considerably easier.
[snip]
We've had tools like this on toolserver before, with decent
performance and the ability to be embedded into commons via cross site
JS hacks, and been told in no uncertain terms that the community
policy is "do not over categorize; things should be placed in the
fewest and most specific categories possible". On commons there are
quite a few contributors who spend all of their time converting the
set of categories on an image to the one or two most specific
categories.
Please pardon Dschwen's frustration: because it seems like people are
constantly waving their arms and saying that there will be some
wonderful technical solution right around the corner for the problems
created by the current categorization approach (never mind that some
of them, such as the extreme semantic drift, are unsolvable with a
technical solution).
For commons, and a lesser degree other projects, the limiting factor
in the usability of an intersection tool is less the lack of one and
more the insistence of the userbase of using categories in a manner
which is generally incompatible with them.
For the purposes of MediaWiki these factors are not important, I
suppose, but it does explain the sceptical response.