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Re: RFC 2616 vs. AWWW

From: Pat Hayes <phayes@ihmc.us>
Date: Fri, 12 Oct 2007 10:20:41 -0500
Message-Id: <p06230904c3353da38c43@[10.100.0.19]>
To: "Jonathan Rees" <jonathan.rees@gmail.com>
Cc: public-semweb-lifesci <public-semweb-lifesci@w3.org>

>As usual, I like your explanation very much. It borders on sophistry,
>but that doesn't bother me much, or won't until my next conversation
>with someone who's upset about the use of http: URIs to refer to
>things that aren't network resources.
>
>I've copied your email to the wiki page, reformatted a little bit.
>Hope that's OK. I also softened my conclusions a bit.
>
>The httpRange-14 resolution [1] is about identification (of a thing
>by/to an http server), not reference. If we translate it from the
>language of AWWW to the language of RFC 2616, we get
>
>  * If a [network] resource responds to a GET request with a 303 (See
>Other) response, then the thing identified [to the HTTP server] by
>that URI could be any thing;
>
>which is absurd since the thing identified by the URI is the resource
>that's responding to the GET. If I understand you correctly you would
>change the 'identified [to the HTTP server]' to 'referred to [by
>someone]', yes?

Yes, exactly. There is a history here, of the word "identifies" 
having been used ambiguously to mean either 'refers to' or the older 
sense, which I like to gloss as 'accesses'. So in some documents it 
means one sense, others another; and in some it means both, which 
gets very confusing.

>It's not clear who or what is doing the referring -
>maybe RDF documents on the same server, or something like that.

Right. The technical thing to say would be something like: for 
purposes of determining reference, yadda yadda.

>(The text [to the HTTP server is mine, but I believe is a correct
>interpretation of the RFC.)
>
>The 200 rule would be
>
>  * If a [network] resource responds to a GET request with a 2xx
>response, then the thing identified [to the HTTP server] by that URI
>is a [network] resource;
>
>which would be tautologous (unless different agents are doing the two
>acts of identifying??)

No, its just plain tautologous :-)

>, requiring a similar change 'identified [to the
>HTTP server]' to 'referred to [by someone]'.

Technically, the URI refers. So what it should say is:

* If a network resource responds to a GET request with a 2xx 
response, then that URI must be understood as referring to that 
network resource.

>Oddly, this rule doesn't tell you which network resource is
>referenced; it could be one that's unrelated to the network resource
>that responds to the GET.

Then that is a mistake, it should refer to the same resource.

>(Aside: As I have said before, the text also needs to be changed to
>say that the 200 only ''states'' that the referenced resource is a
>network resource, not that it ''is'' one, since the server could be
>wrong.)

? I don't follow you. If any response other than a 404 comes back, 
then certainly there must have been a network resource there to emit 
the response. No room for error there, right? And what the 
httpRange-14 decision says (should say) is, then that URI should be 
understood as denoting that actual network resource. That matters to 
the sender of the GET, usually, more than than to the server. If Im 
messing around with URIs, I don't really care what the server thinks 
they denote. Its job is just to respond to my requests, not to have 
opinions about them.

>httpRange-14 screws citation - we can't use URIs identifying
>200-responding network resources to refer to things like journal
>articles, which are (ontologically) not network resources even if
>they're published online

Oh, I think we can let them be network resources. Being anal about 
avoiding ambiguity can only be taken so far before it starts getting 
irrational. BUt if you want to be, you'd have to distinguish the 
online document from the actual article (whose URI would 303 you to 
something else, which could actually be the online document, seems to 
me.)

Pat

>  - but that's another story (yes, I'm baiting
>you).

Grrrrr.

>
>[1] http://lists.w3.org/Archives/Public/www-tag/2005Jun/0039.html


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Received on Friday, 12 October 2007 15:20:59 GMT

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