Sorry, I should have been clearer in my explanation - it's actually not difficult at all to separate between classes and individuals: the former are in the "Category:" namespace, the latter aren't. So if you have a page called "Garfield", it would be a member of "Category:Cat". On the other hand, if there were a page about the specific attributes of cats, it would be called "Cat", which would be a page distinct from "Category:Cat". (Whether "Cat" should be a member of "Category:Cat" is its own question - I would argue no.)
One way to get around the naming confusion, and the way I recommend, is to always give categories plural names - so "Garfield" would instead be a member of "Category:Cats", which would be a subcategory of "Category:Mammals", etc. That tends to clarify the distinction between classes and individual instances. -Yaron On 7/4/07, Fernando Carpani - INCO <[EMAIL PROTECTED]> wrote: > Hello. > How you say that Garfield (an individual) is a Cat (a collection of > individuals)? > If you use the same relation "is a" you might be in logical > troubles....you need other role like "belongs-to" or "instance-of"... > Mammal or Cat are collections of individuals... but Garfield is an > individual. > Normally, we try to keep separate the collections and the individuals. > > The mathematical relation between a category and a simple page is "page > belongs to Category". > But between a categoy and any subcategory is "subcategory subset of > Category". > > Is not the same part-of or belongs-to that subset-of. > > I think that it's better follow a logical point of view at the moment of > represents the data. > > > Fernando Carpani. > > > Emanuele D'Arrigo wrote: > > >On 7/4/07, Olivier Dameron <[EMAIL PROTECTED]> wrote: > > > > > >>>can a relation "is a" be used to completely replace categories? > >>>Can you think of any advantage/disadvantage with this approach? > >>> > >>> > > > > > > > >>"is a" represents specialization (e.g. Cat is-a Mammal, which means > >>that all the instances of Cat are instances of Mammal) > >> > >> > > > > > > > >>Categories are organized along the "is a" hierarchy, but also follow > >>the "narrower than / broader than" relation (e.g. Algebra is a > >>subcategory of mathematics), which is more like a kind of part-of > >> > >> > > > >But then why not to use "is a part of" or is "a type of" instead of > >categories? It seems to me that categories are redundant once > >you have relations, and what's worst, depending on the context, > >they seem to be in-lieu of different type of relations. > > > >I'm confused! > > > >Ciao! > > > >Manu > > > > > > > > > ------------------------------------------------------------------------- > 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 > ------------------------------------------------------------------------- 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
