Subject: Re: URIs vs URLs? Resent-Date: Sat, 18 Dec 1999 15:10:57 -0500 (EST) Resent-From: www-rdf-interest@w3.org Date: Sat, 18 Dec 1999 21:10:33 +0100 From: Jonas Liljegren To: Dan Brickley , RDF Intrest Group References: 1 Dan Brickley wrote: > > On Mon, 13 Dec 1999, Jonas Liljegren wrote: > > > Daniel LaLiberte wrote: > > > > > > Jonas Liljegren writes: > > > > Now, assuming MD5 model URIs, we would like to differ between: > > > > > > > > 1. The URI of the service > > > > 2. The URL of the service > > > > 3. The URI for the physical person > > > > 4. The URI of the model describing the person > > > > 5. The URL of the model describing the person > > > > 6. The URI of the model describing the service > > > > 7. The URL of the model describing the service > > > > > > I'm curious what you are thinking of as the difference between > > > URIs and URLs. > > > > With the suggested RDF API, the model URI would be a MD5 digest, > > but the model URL would be the place there you can get it. > > > > To minimize confusion about what the URI denotes, the person URI > > should not be a URL leading to a document. All URIs leading to a > > document would be seen as the URI of that document, rather than > > the URI for something in "the real world". > > > > See the previous discussion on this: > > > > http://lists.w3.org/Archives/Public/www-rdf-interest/1999Dec/0055.html > > I disagree. Being able to 'ask the Web' about a given URI (real > world or not) is a feature not a bug. Content and language > negotiation already ensures that that is a complex relationship > between resources and the document(s) available by talking to > services associated with those resources. The URI for the W3C logo > being a classic example of this: there is a URI for the image 'in > the abstract' and two URIs for different file formats (png and gif). > > RDF is defined in terms of resources and URIs. The RDF > specifications do not invoke the URI/URL distinction, and this is > for good reason. If we want to distinguish between URI of a service > and URL of a service, we should make sure we use different URIs for > those objects, and name the relationship between the two. Well. That was what I was trying to say. That there are a URI for the origin of a model and a URI for the model itself. I did this separation for clarification. I had always imagined that the model URI would be the URI of its origin. Since it is important to know if you are refering to a description of something or the thing in itself, it could help the understanding to let the URI of the description be the description rather than the ting it describes. http://abc/jonas could be used as the URI of the person jonas. But this could also be the URL of a document describing that person. If that were the case, what URI would you use to refer to the document, rather than the person? -- / Jonas - http://paranormal.o.se/perl/proj/rdf/schema_editor/