S Page wrote: > Jeff Thompson wrote: >> average users cannot tell the >> difference between "instance of" and "subclass of", and so we are >> stuck with >> only "category". Is that why the decision was made to try to get by >> with the >> ambiguous use of "category"? > > MediaWiki does handle the distinction. Articles in a category are > rdf:type (which imples "instance of a class") and subcategories of a > category are rdfs:subClassOf. (If you do RDF export of article and > category pages, you can see this.) I'm no RDF expert, but this seems a > reasonable choice.
Thanks for the feedback. I understand this distinction. It's intuitive when articles are for instances and categories are for classes. But there are other common cases. For example here is an article about the naughty panda "Gu Gu": http://en.wikipedia.org/wiki/Gu_Gu The authors correctly put this article in Category:Famous_pandas: http://en.wikipedia.org/wiki/Category:Famous_pandas which correctly is a subcategory of Category:Giant_Pandas: http://en.wikipedia.org/wiki/Category:Giant_Pandas But confusion arises because "Giant Panda" is important enough to have its own article: http://en.wikipedia.org/wiki/Giant_Panda This is an article, but about a class, not an instance. Notice that the authors are trying to a subclass relation by putting the article in Category:Bears. But since it's an article, this incorrectly means "Giant Panda" is an *instance of* Category:Bear. A possible solution: In Category:Giant_Pandas it does link to the Giant_Panda article. This link could be tagged as Relation:Category_about: http://ontoworld.org/wiki/Relation:Category_about then, the inverse Relation:Has_category on the "Giant Panda" article automatically replaces the incorrect [Category:Bear]. This is all necessary because the "Giant Panda" article is for a class, not an instance. To make things worse, "Giant Panda" is in fact an instance, but of the higher-level Category:Endangered_Species: http://en.wikipedia.org/wiki/Category:Endangered_species and the "Giant Panda" article *is* correctly in this category as an instance. To continue to make things worse, Category:Endangered_species also has its own article page: http://en.wikipedia.org/wiki/Endangered_species This is an article, not for an instance but for a "class of classes"! :-) > You bring up good points about the ambiguity of categories of categories > in MediaWiki. This should definitely be noted somewhere in SMW help. We need to untangle category pages from article pages about the same category, so that the author does not try to put the article page back in the same category again, or try to use the article to show subclass relations. I think the best way is Relation:Category_about, already used on ontoworld. Do you think the SMW help should just explain the ambiguity, or also suggest a solution? - Jeff ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Semediawiki-user mailing list Semediawiki-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/semediawiki-user
