- From: Booth, David (HP Software - Boston) <dbooth@hp.com>
- Date: Fri, 28 Apr 2006 23:40:08 -0400
- To: "Pat Hayes" <phayes@ihmc.us>, "Frank Manola" <fmanola@acm.org>
- Cc: <public-swbp-wg@w3.org>, "Guus Schreiber" <guus@few.vu.nl>, "Steve Pepper" <pepper@ontopia.net>, "Mark van Assem" <mark@cs.vu.nl>, "Ralph R. Swick" <swick@w3.org>
> From: Pat Hayes: > > From: Frank Manola > . . . > >Take the case of an RDF vocabulary referenced by a single URI, say > >http://example.myvocab. However, "under the covers" there are > >really two documents available, http://example.myvocab.rdf and > >http://example.myvocab.html. A user may want either the rdf or the > >html version of the vocabulary, depending on what she/he is trying > >to do, and the discussion in http://www.w3.org/TR/swbp-vocab-pub/ > >shows how you can get the version you want if you ask simply for > >http://example.myvocab. Now, my understanding is that: > > > >a. There are *three* resources here, http://example.myvocab, > >http://example.myvocab.rdf, and http://example.myvocab.html. These > >are all resources in spite of the fact that http://example.myvocab > >is in some sense "more abstract" (less of a specific representation) > >than the other two. > > I have trouble here understanding what http://example.myvocab > actually *is*. If it is a resource, what can possibly be a > representation-1 of it? Its relationship to the 'real' html and rdf > resources doesn't seem like that of a resource to representations-1 > of the resource, since the distinction is not one of state at a time, > but is determined by the request; and representations of them are, > well, of them, so not of it. So it seems to have no representations-1 > at all. (??) Well, no. Two different resources can have the same "representation", just as two different URIs can identify the same resource. > . . . > >c. *All* of these are "information resources", in that their > >"essential characteristics can be conveyed in a message". That is, > >considered independently, the essential characteristics of > >http://example.myvocab.rdf can be conveyed in a message, the > >essential characteristics of http://example.myvocab.html can be > >conveyed in a message, and presumably the essential characteristics > >of http://example.myvocab can be conveyed in a message (although > >what actually gets sent is a representation of one of those other > >files). > > Well, but that is the fatal objection. Neither of these would convey > all the essential characteristics of http://example.myvocab, > precisely because it can be either RDF or HTML, but neither of those > can be the other. Unlike them, it is a chimera. Excellent point! Then in some sense, the resource associated with http://example.myvocab is the union of the resources associated with http://example.myvocab.rdf and http://example.myvocab.html . However, the WebArch definition of "information ressource" permits representations to have "varying degrees of fidelity"[10]. So I suppose in some sense, when http://example.myvocab is dereferenced and only an instance of http://example.myvocab.rdf is returned, perhaps that is considered a low fidelity "representation" of the information resource. David Booth
Received on Saturday, 29 April 2006 03:45:20 UTC