Hi,

Perhaps i expect to much of categories but I still do not see the difference between categories and other articles.

Evan Prodromou wrote:

From a graphical level, part-whole implies a tree structure

This is only true for one type of part-whole-relationship. There is Part-of-Time, Part-of-Space, Part-of-Belonging etc. With all this posibilities you end up in a multiple hierarchy.

OK. I took "dividing an article into subtopics" as "dividing an article into parts". I think there's ways that "subtopics" could be parts, and ways that "subtopics" could be members of a category.

No way. The difference between Part-whole-relationship and instance-of-relationship is too slightly to bee recognized by a large community in the same way. In a short article about Northern Ireland there could be a chapter about National parks of Northern Ireland (part-of). Somebody moves it into an article of it's own. In short time there will be more than one parent of this article (Irleand, National Parks, Conservation in the United Kingdom...).

Erik wrote:

Category pages are not articles. Like talk pages and meta pages, they should be logically separated from articles, which has numerous benefits (easier searching/filtering, counting etc.)

If you mean articles containing *only* a list of other articles that are categorized under the same topic you are right. But there are a lot of real articles that *also* contain lists of subtopics. A quick example:

In [[en:Statistics]] there is a the following part "Some sciences use applied statistics so extensively that they have specialized terminology. These disciplines include:" and a list containing "Biostatistics, Business statistics, Economic statistics, Engineering statistics, Population statistics, Psychological statistics, Social statistics, Process analysis, Chemometrics".

I think most people would categorize these articles in [[category=Statistics]] or [[category=Applied statistics]]. With your approach we´ll have

1.) an automatically generated page [[category:Statistics]] and 2.) the manually generated list in the article [[Statistics]]

That does not seem very smart. By the way an article can be categorized in multiple topics so there may be multiple manually generated lists in different articles that are only connected via normal links and some category-pages.

If category-pages should get a different namespace like the Talk-pages there will be a automatically generated category-page for each article. In most cases It will be empty or small. There should be a way to include it's content in the article for instance with something like {{MySubtopics}}

Greetings Jakob