From: Yaron K. <ya...@gm...> - 2007-07-04 21:24:30
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The big reason to use categories instead of relations for "is a" relationships is that categories support inheritance, while relations don't. To use Olivier's example, if you classify a cat as being of category "Mammal", and "Mammal" being of category "Animal", then you can do a query on [[Category:Animal]] and cats will show up, assuming they fit the other query criteria. You can't replicate that behavior with relations. -Yaron On 7/4/07, Emanuele D'Arrigo <ma...@gm...> wrote: > On 7/4/07, Olivier Dameron <oli...@un...> 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 > > -- > Emanuele D'Arrigo > vfx free electron > > ------------------------------------------------------------------------- > 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 > Sem...@li... > https://lists.sourceforge.net/lists/listinfo/semediawiki-user > |