- From: John Cowan <cowan@mercury.ccil.org>
- Date: Thu, 2 Oct 2003 07:44:00 -0400
- To: Patrick Stickler <patrick.stickler@nokia.com>
- Cc: ext Garret Wilson <garret@globalmentor.com>, "ext Hammond, Tony (ELSLON)" <T.Hammond@elsevier.com>, www-rdf-interest@w3.org, uri@w3.org
Patrick Stickler scripsit: > It is an understandable common misconception that what an HTTP > server actually returns is what is denoted by the URI. The fact > is that we can never be absolutely sure what resource a URI > denotes based on what is returned by a server. In some cases > it's easier to guess than other cases, but typically you can't > ever be sure. Hence the car/document problem. This characterization of the problem is far too mild. Consider the resource whose URI is http://www.tagyerit.com/images/adopted/shakespeare.jpg . You can't do a direct GET on this any more, but it's still available (for now) in the Google cache at http://images.google.com/images?q=tbn:IbW4adfRGVkC:www.tagyerit.com/images/adopted/shakespeare.jpg If you retrieve this resource, you will get a sequence of bits labeled image/jpeg. But what is the resource? Is it Shakespeare? Is it a (generic) picture of Shakespeare? Is it this *particular* image of Shakespeare? Or is it something else altogether? Nobody can say, probably not even the person who posted the picture to the Web. > And hence the reason for URIQA. To be able to obtain an authoritative > answer to the questions "What does this URI denote, and what is > that thing like?". A representation of the resource might be able > to give a human some clues, but being able to obtain a formal, > precise description of the resource is much better. A fine thing indeed. How would you formally characterize the relationship of the above URI to Shakespeare? -- If you understand, John Cowan things are just as they are; http://www.ccil.org/~cowan if you do not understand, http://www.reutershealth.com things are just as they are. jcowan@reutershealth.com
Received on Thursday, 2 October 2003 07:44:24 UTC