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Re: FW: removing constraints on 'resource' [024-identity]

From: Pat Hayes <phayes@ihmc.us>
Date: Thu, 27 May 2004 10:02:42 -0500
Message-Id: <p06001f3abcdbab3b40c7@[]>
To: "Williams, Stuart" <skw@hp.com>
Cc: Dan Connolly <connolly@w3.org>, uri@w3.org, msabin@milessabin.com, ;, tbray@textuality.com, ;, joshuaa@microsoft.com, Tim Berners-Lee <timbl@w3.org>
>I don't know if you've seen this thread.

I hadn't, thanks.

>  Dan does invite comment from you
>(and specific others) but appears to have accidently left you off the Cc
>-----Original Message-----
>From: uri-request@w3.org [mailto:uri-request@w3.org] On Behalf Of Dan
>Sent: 24 May 2004 21:54
>To: uri@w3.org
>Cc: msabin@milessabin.com; tbray@textuality.com; joshuaa@microsoft.com
>Subject: removing constraints on 'resource' [024-identity]
>"Anything that has been named or described can be a resource."
>-- http://www.gbiv.com/protocols/uri/rev-2002/rfc2396bis.html#overview
>Based on discussion with TimBL and Roy and a few others, as well as review
>of this issue...
>024-identity Resource should not be defined as anything that has identity
>it seems more straightforward to just say
>	A resource can be anything; familiar examples include an
>document, an image, a service (e.g., "today's weather
>	report for Los Angeles"), and a collection of other resources,
>	but there is no constraint on what is a resource.

It is indeed more straightforward and avoids a sinkhole of debate 
about what 'identity' means. However, this particular wording is 
still rather odd , in that the 'familiar examples' given are all 
suggestive of the more limited notion of 'resource' which would be an 
appropriate understanding of the intended meaning by someone who came 
to this discussion with a background in network architecture, viz. an 
information item which can be accessed or used via a network 
protocol. So this clarification does nothing to resolve the 
fundamental ambiguity/ambivalence in the overall document which I 
referred to in my original comments.

BTW, the diagram cited below (Im looking at the one at 
http://www.w3.org/DesignIssues/diagrams/URI-space.png ) directly 
embodies that confusion/ambiguity very clearly. There are two black 
arrows at the bottom, one going from 'hypertext' to 'anchor', the 
other going from 'semantic Web' to 'anything'. THESE TWO 
refers to identification on a network, and belongs in my "C' 
category: the second arrow is denotation, which has nothing to do 
with computation and belongs entirely in the D category. The first is 
supposed, by its very nature, be computable (given the state of the 
network) and requires uniqueness of identification: neither of these 
properties hold of the second. The second can refer to anything: the 
first, by its very nature, cannot.  The second must be understood 
relative to an interpretation: the first cannot be that ambiguous but 
must be determined by the state of the Web.  The entire force of my 
extended attempt to deconstruct the confusion in the TAG architecture 
document can be summarized by the observation that these two 
relationships, shown in this diagram by identical (and parallel) 
arrows, are FUNDAMENTALLY DIFFERENT.  Calling them both 
'identification' is not a good strategy: it is in fact little more 
than a pun. Applying criteria which make perfect sense for one to the 
other produces nonsense and confusion.

To make the point in another way, note that HTML consists largely of 
text, and text  denotes. (Text has been denoting since before 
recorded human history, and I don't think that the Web is going to 
stop that happening.) So there should be TWO arrows coming from the 
left-hand box, one going to 'anchor' and the other, understood as 
exactly similar to the arrow on the right, going to 'anything'. One 
of those arrows is access, the other is denotation or reference. A 
priori, they have nothing whatever to do with one another and can be 
assigned values independently. (In case there is an objection along 
the lines that what text refers to has got nothing to do with network 
architecture: I agree, and that is precisely my point. What the 
RDF/OWL text *refers* to has got nothing to do with Web architecture 
either. Architecture and semantics are (to a first approximation) 
orthogonal matters. By confusing access with denotation, and 
referring to them both as 'identification', the Tag document distorts 
a two-dimensional reality into a one-dimensional picture.)

>Public discussion of http://www.w3.org/TR/webarch/ suggest that this
>unconstrained definition of 'resource', along with a separate term for a
>smaller set of "information resources" is a useful way to describe the role
>of URIs in Web Architecture.

Well, it might be if the document was rewritten carefully paying 
attention to this distinction, and not applying advice suitable to 
the special case to the more general case. However, the result would 
be that almost the entire document would be about 'information 

>(we haven't finished the text yet, but you can see a diagram at
>   http://www.w3.org/2004/05/URI-space-small.png
>   http://www.w3.org/DesignIssues/diagrams/URI-space.svg
>and some notes on the discussion at
>   http://www.w3.org/2004/05/14-tag-summary.html#httpRange-14-1 )
>The unconstrained definition of 'resource' is also what was imported into
>the RDF specification:

Well, yes, but only because you told me that was obligatory, and in 
my Webbish innocence I believed you :-)


>   The things denoted are called 'resources', following [RFC 2396], but
>   no assumptions are made here about the nature of resources; 'resource'
>   is treated here as synonymous with 'entity', i.e. as a generic term
>   for anything in the universe of discourse.
>     -- http://www.w3.org/TR/rdf-mt/ aka
>	http://www.w3.org/TR/2004/REC-rdf-mt-20040210/
>I think this captures the input I got from TimBL on the matter; could you
>confirm, TimBL?
>Roy's input to the recent discussion was mostly in the role of editor,
>relaying comments on earlier URI spec drafts. From the archives, it seems
>that at Miles Sabin, Pat Hayes, Tim Bray, and Joshua Allen had opinions on
>the matter. If you would care to comment on this proposal, I'd appreciate
>Dan Connolly, W3C http://www.w3.org/People/Connolly/

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Received on Thursday, 27 May 2004 11:02:45 UTC

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