- From: Mikael Nilsson <mikael@nilsson.name>
- Date: Mon, 26 Nov 2007 12:20:33 +0100
- To: Dan Brickley <danbri@danbri.org>
- Cc: Tim Berners-Lee <timbl@w3.org>, wangxiao@musc.edu, Alan Ruttenberg <alanruttenberg@gmail.com>, Chimezie Ogbuji <chimezie@gmail.com>, Pat Hayes <phayes@ihmc.us>, www-tag@w3.org
mån 2007-11-26 klockan 10:48 +0000 skrev Dan Brickley: > One of the ways we can be clearer about RDF/OWL class definitions, is by > being clear about which things are *not* in some class we define (and > ideally also giving some explanation). Yes, I agree. > For example, considering "books", > which of the layers of the FRBR conceptualisation (work, expression, > manifestation, copy) are information resources in the AWWW sense, and > which aren't. Perfect example, thank you. > > RDF terms are also slippery things, but at least they're a W3C creation, > so getting an account of whether RDF terms are "information resources" > should be a smaller task. I'm yet to hear a knock-down argument as to > why RDF terms (dc:creator, foaf:OnlineAccount etc) are not human works > with http-accessible representations, just like Web pages and books. I > don't really mind putting in the 303 redirects, but I still haven't come > to any clear rule-based or intuition-based sense of what things are in > or out of the awww:InformationResource class. A lot of the http-range > discussion has been in terms of people, cars, etc; RDF properties are > much closer to the borderline, and so might be a useful category of > thing to help make these definitions sharper. I happen to think Properties are non-IR, and I think there are compelling arguments for that. I think the problem is that people, cars, etc all have an existence outside the Web - they are physical things. The class of things you are thinking about seem to be abstract entities of different kinds, correct? If you were to say that a Property is an IR, then that same argument applies to all abstract entities. Concepts, classes, mathematical functions, etc etc. But even so - timbl's distinction between the content of a thing and descriptions of that thing apply. That is: a description is not the same as the content of the thing. Or put in other words, what *would* be the content of dc:creator? I can't find any message that would convey anything other than the definition. One potential representation would be all pairs of (subject, object) to which the property applies. Now, RDF Semantics defines a Property to be something else than this set, so that is not appropriate either. So if we can't imagine a representation of the *content*, it's not an IR. /Mikael > > cheers, > > Dan > > -- <mikael@nilsson.name> Plus ça change, plus c'est la même chose
Received on Monday, 26 November 2007 11:20:46 UTC