[WikiEN-l] Category destruction

[Tracy Poff]

On 4/30/07, Marc Riddell <michaeldavid86 at comcast.net> wrote:
> In my work I have access to a database of thousands of case studies of
> persons who have been formally treated for various psychosocial disorders.
> The information does not include personal identification materials, just
> age, gender and other demographics, plus their diagnosis, course of
> treatment and outcome.
>
> In each record there is a list of identifying codes. If the person's primary
> diagnosis was chemical dependency, the (main) code for this is entered; if
> that person's primary chemical of use was cocaine, the (sub) code for this
> is also entered, etc.
>
> Now, if I want to call up all cases of chemical dependency, I enter its code
> and I have a list of these cases to study. If I want only those cases where
> the primary chemical of use was cocaine, I would enter that code. For this
> to work, BOTH the main and sub codes must be entered in each case.
>
> This is what I am asking for in WP. That is why both the main and sub
> categories need to be entered into each Article.

But this may not be the best way to do things. Consider the following
two categories:

 Continents>
 Continents>Europe>England>People from England>Musicians from
England>Heavy metal guitarists from the England

If we did as you say, this would place Jimmy Page, the guitarist from
Led Zeppelin, in the same category as Africa. Is that useful?

Imagine if I wanted to find all of the musical groups except for folk
music groups. In order to do this, I would need some way of performing
unions on the subcategories of "Musical groups by genre" (or whatever
it is called). If I could do this, there would be no need to place the
articles in subcategories and parent categories. So, the only purpose
that would really be served by doing this is finding all articles
anywhere below a given category in the tree. However, this would be
served equally by a union function, which would be useful for other
applications as well. Doing as you say would make it impossible to
distinguish Jimmy Page from Europe without having the extra
union/intersection functionality as well.

The best solution, in my opinion, would be to implement unions and
intersections, using which we could do pretty much whatever we wanted.
Placing articles in both subcategories and parent categories, though,
would be less than useful.

Tracy Poff