There is a problem with this: Handling categories equal to rdf:instanceOf might work well for new wikis, but it works terribly bad with the current category practice in Wikipedia. The Wikipedians probably won't like to completly rewrite the categories.
Anyway, the Bollywood-Film might get represented as: (Agar , instance of , Indian Film) (Agar , produced by , Bollywood) (Agar , language , Tamil) (Indian Film , subclass of , Film) (Indian Film , produced in , India) (Bollywood , instance of , film industry) (Tamil , subclass of , Hindi language) (Hindi language , instance of , Language) (Hindi language , developed in , India) ... ys, MovGP0 Yaron Koren wrote: > This issue has come up before - it's true that using categories to > indicate type seems to somewhat fly in the face of the principle of > using attributes and relations for everything. They're used, in place > of "Instance of" or "Is a" or whatever else, because they allow for > inheritance - if a page is a member of a category, it is also a member > of all the categories that category is a member of, etc. This is a > very useful property. > > And it's not really a violation of principles, because you can think > of "category" as a third semantic relationship, one with a very > specific meaning - categories can get queried and are exported into > RDF, just like attributes and relations. > > It's true that Wikipedia uses categories for many different purposes > (more than just those 3, in fact - there are also categories like > "Articles that need more references", etc.), and many of these make > more sense as attributes and relations. However, in SMW wikis, > categories are still appropriate for one kind of semantic tagging - > "Instance of" relationships. In the example you mention, a category > like "Films" might do the job. Everything else, like language, country > of origin and genre, could be done via attributes and relations. > > -Yaron > > > On 5/26/07, Jeff Thompson <[EMAIL PROTECTED]> wrote: >> On this page: >> http://ontoworld.org/wiki/Relation:Instance_of >> it says that Relation:Instance_of and Relation:Subclass_of are deprecated and >> you are only allowed to use the category system. >> Maybe it was decided that 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"? >> >> For example, here is the Wikipedia category Hindi-language_films: >> http://en.wikipedia.org/wiki/Category:Hindi-language_films >> Note that this category belongs to 3 other categories in 3 very different >> senses: >> >> 1. Subclass of: "Indian_films". A specific film that is a Hindi language >> film >> is also an Indian film, so the category Hindi-language_films is a >> subclass of Indian_films. >> 2. Instance of: "Films_by_language". A specific film that is a Hindi >> language film is *not* a film by language. Rather, it is the >> category Hindi-language_films that is an instance of the higher-level >> category of Films_by_language, along with other categories like >> Tamil-language_films. >> 3. Somehow related to: "Bollywood". The category Hindi-language_films has >> something to do with Bollywood, but the relationship is not specified. >> However, isn't that the whole point of the Semantic Web, to make the >> relationships >> explicit? But the category system is as generic as an untagged link in >> Web 1.0 that we are trying to fix with Web 3.0. >> >> Is there a web page or statement about how the Semantic Mediawiki will >> handle these 3 different types of relations, if the more meaningful >> relations are deprecated and we are only allowed to use the category system? >> Is it a totally closed issue? >> >> Thanks for any help, >> - 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
