[Commons-l] Our categories are broken, very broken

[Daniel Kinzler]

> I think en: and commons prove you can't maintain a tree in wiki format.
> 

Well, enwiki is by *far* the worst. When I analysed category structures of
wikipedias, I usually found an average depth ovf about 10 and a couple of cycles
with a circumference of about 20. enwp has hundreds of cycles, many of which are
huge. The largest one i found has over 300 entries. That's insane.

So, basically: the fact that enwiki got it wrong proves nothing. Most other
'pedias do way better.

But categories as we have them are far from perfect, and it would of course be
nice to be able to do "deep intersection" of categories. But "simple" tags would
have two big disadvantages: ambiguity, and lack of a navigational structure. If
we can get intersection, but retain the ability to categorize categories, that
would be great. However, this means we need "deep intersection", which is
something relational databases are notoriously bad at. I don't know how or if
this can be implemented efficiently.

-- daniel