Simetrical wrote:
Since we've also been discussing the problems of implementing "Category Intersection", an interim solution could be repopulating parent categories and "hiding" intersection categories. Fully populated parent categories are the norm in some projects like German Wikipedia and they also appear sometimes in English Wikipedia (eg. Category:Operas). I have a proposal posted currently about fully populating "Index" categories at en:Wikipedia talk:Categorization, and it would be much improved if the intersection categories could be hidden. The primary reason we have been deleting intersection categories is because they clutter articles. If they didn't clutter articles, they wouldn't be a problem.
A very reasonable idea, that can be implemented Right Now with little effort on the user level. Important or interesting intersections can be manually populated, or populated in batches with bots. It's not as good as a real solution, but it should work well enough.
Fabulous! Can we do it? The ability to hide categories from pages will have a huge effect on categories. One that will be quite positive, I think. The current discussion started because a bot was set to repopulate categories, so the bots are ready. If this is going to happen, we need to start discussions about guidelines beforehand and get people on board, so please give us some warning in advance. If it literally can happen "right now", I'd actually prefer it be left turned off until us category wonks can generate a plan.
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There would need to be a naming convention for the automatically generated categories, perhaps using a double colon -- so the intersection of Category:Mozart and Category:Operas would generate Category:Mozart::Operas. . . .
By this point, the feature you describe would be more difficult to implement than just implementing real and properly efficient category intersection with Lucene or something. When you realize that to get your hack working properly, you need to implement so many workarounds than the real feature would be easier, it's time to discard the idea of a hack.
Forget I ever mentioned it. I'll wait for the real thing. With the first step of making hidden categories we can set to work on repopulating categories. This will make the transition to Category Intersection much smoother.
--Samuel Wantman
[en:User:Sam]