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Re: [pedantic-web] Re: The OWL Ontology URI

From: Pat Hayes <phayes@ihmc.us>
Date: Thu, 13 May 2010 10:53:36 -0500
Cc: Jonathan Rees <jar@creativecommons.org>, AWWSW TF <public-awwsw@w3.org>
Message-Id: <321DE57F-563E-4F7D-B05D-38217C76E818@ihmc.us>
To: Dan Connolly <connolly@w3.org>

On May 13, 2010, at 10:18 AM, Dan Connolly wrote:

> On Thu, 2010-05-13 at 00:03 -0500, Pat Hayes wrote:
>> Dan, I don't think I've got my point across, and its getting lost in
>> all this confusion about information resourceness. Its really a very
>> simple point, and I can make it with a very simple example.   
>> Suppose A
>> is an RDF graph, and B is an RDF/XML file which encodes/is a surface
>> syntax of/represents (choose your favorite terminology) that graph A.
>> And suppose U is a URI which "identifies" B, in the sense that what
>> you get back, when you do an HTTP GET using U, is a
>> 'representation' (in the REST sense) of B with a 200 code attached.
>> That is, the relationship between U and B is exactly like that  
>> between
>> the URI of a web page, and the web page itself.
> That's perhaps a different architecture; i.e. a different way of  
> looking
> at things than is in webarch and REST.
> A typical web page has various representations over time, and
> when we link to the web page, we don't link to any one of them,
> but to all of them (indexed by time). So (in webarch/REST) U
> isn't a URI for B, but for something that B represents.

Yes, I know. But lets take a very very simple case, to make the point,  
where the resource does NOT change over time. Many  Web resources are  
like this; and the point being discussed here doesn't seem to depend  
on B being dynamic in this way.  (Although, if it is part of the  
nature of a REST-identifiable resource that it is dynamic, then that  
is even more reason why an RDF graph - a mathematical set - can't be  
one of them.)

> Again, please take a look at the figure in the webarch intro
>  http://www.w3.org/TR/webarch/#intro
> There we see that http://weather.example.com/oaxaca identifies
> a weather report (a web page) which is represented by
> an HTML document.

And when that document was first drafted, I asked, what exactly IS  
this thing called a 'weather report'? And the only answers I got  
(other than being told not to ask such questions) were along the lines  
of it being a computational entity which emits XHTML when prodded by a  
GET, ie a Web page. I know in REST it is, formally, a function from  
times to representations (of it), which is mathematically correct but  
wholly uninformative as to what kind of thing it is, as it can be  
applied to any function from times to anything.

>> My point is simply that under these circumstances, we are pretty much
>> obliged by http-range-14, as I understand it, to say that U denotes  
>> B;
>> that is, it denotes the thing it HTTP-identifies.
> You keep saying that, and I keep asking how you come to that
> conclusion. I thought perhaps using more formal terms and going
> slower would help, but evidently not. Oh well.

If this understanding of http-range-14 is wrong, then please tell me  
exactly how, and what I should understand it to mean. But please do so  
without using the term "information resource". BTW, being more  
"formal" doesn't help, no.


> [... I didn't read the rest carefully, since it seems to be based
> on premises that I don't understand. ...]
> -- 
> Dan Connolly, W3C http://www.w3.org/People/Connolly/
> gpg D3C2 887B 0F92 6005 C541  0875 0F91 96DE 6E52 C29E

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Received on Thursday, 13 May 2010 15:54:42 UTC

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