At 03:22 AM 6/8/2004 +0200, Anthere wrote:
[[list of museums in Australia with a chinese flag hanging above the entrance door]] is of no use.
Search "[[museum]]" where "[[country]] is 'australia'" and "[[topic]] is 'China'" is useful.
To be useful, meta-tags must be large rather than very specific. Query gives the specificity.
But thanks to subcategorization, they can be _both_. [[Museums in ohio]] can be a subcategory of [[Museums]] along with all the other [[Museums in <location>]] subcategories, and then all you need to do is throw in a mechanism for referring to all the articles in a category tree and you can treat [[Museums]] as if it contained all museum articles everywhere. If you're already proposing a query language for manipulating categories this seems a fairly trivial extension to it to me.
I've been wavering a bit, but I think I'm coming down pretty solidly in the fine-grained categorization camp. The other day I was working on moving the articles in the [[North American Rivers]] category to the [[North American rivers]] category (note capitalization), and started putting the articles into [[Idaho rivers]], [[Alberta rivers]], etc subcategories instead because the list was so big and generic otherwise. I then found it trivially easy to stick those subcategories under the relevant geographic categories as well ([[Idaho]], [[Alberta]]), and it occurred to me that it would be fairly easy once I was done to set up [[Mississippi watershed]], [[Colorado watershed]], etc. since in many cases whole entire states drain into those and I could just drop their subcategories in place to include all of their rivers. It would be a whole lot more work if I had to go around to each of those articles and add a new category to every river in North America.
IMO, fine-grained categories provide a convenient "handle" by which groups of articles can be organized in various useful ways, without requiring editors to learn how to deal with query languages doing complicated or mysterious stuff "behind the scenes" or adding lots of high-level category tags to individual articles.