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Re: RFC2396bis wording, opinions?

From: Pat Hayes <phayes@ihmc.us>
Date: Fri, 28 May 2004 11:32:08 -0500
Message-Id: <p06001f42bcdd05aa737e@[10.0.100.76]>
To: Larry Masinter <LMM@acm.org>
Cc: uri@w3.org, "'Tim Berners-Lee'" <timbl@w3.org>, Dan Connolly <connolly@w3.org>

>My goal is to get RFC2396bis to the state where we can publish
>it without having to solve the difficult problems of
>"what is a resource" and "how do URIs work in the semantic
>web to 'denote' as well as 'identify'".

Just as a heads-up, I don't think these are difficult problems at 
all, and that y'all are making things difficult by trying to avoid 
these imaginary problems.  It would all be much simpler if you just 
used words with their normal meanings. The actual situation is 
perfectly clear: URIs have been traditionally used as identifiers, 
but now with the Sem Web they are also being used to denote more 
generally. The exact relationship between these two kinds of usage is 
not entirely clear yet (which is fine, of course).

>So far,
>
>* Tim Bray says he finds the existing text 'tolerable'
>   (wouldn't want to change it) but finds my proposed
>   revision 'much more user-friendly and unsuprising'.
>
>* Al Gilman says (of the revision) 'this is good',
>   although he raises a question about "each URI scheme
>   defines", as to whether it sets up a (inappropriate?)
>   requirement. (I thought I'd wait until it was clear we
>   were starting with my revision before answering that).

This is moving beyond my area of competence, but could you just 
weaken the wording a little, eg "a URI scheme may define" or some 
such?

>So, is there anyone who wants to keep on flogging away
>at the OLD text rather than NEW below?

The NEW is better than the OLD, just on expository grounds, but it 
has the same old problem built into it, in the form of the ambiguity 
about what "identifies" means.  The text changes the meaning in its 
last sentence (I think). Also it seems to imply that something is a 
resource only when its identified by a URI, which has got to be wrong.

Suggested changes to fix these:

-----
The word 'resource' is used as a general term, meaning anything that 
can in principle be identified or denoted by a Uniform Resource 
Identifier; ...

... However, a resource need not be accessible via the Internet; URIs 
might be used to denote human beings, corporations, bound books in a 
library, and even abstract concepts.
-----

OR, slightly better:

-----

The word 'resource' is used as a general term, meaning anything that 
can in principle be identified by a Uniform Resource Identifier; each 
URI scheme defines the range of things that are identified by URIs 
using that scheme. Commonly, URIs are used to identify Internet 
accessible objects or services; for example, an electronic document, 
an image, a service (e.g., "today's weather report for  Los 
Angeles"), a collection of other resources. However, URIs might be 
used to denote entities which are not accessible via the Internet, 
such as human beings, corporations, bound books in a library, and 
even abstract concepts. Some URI schemes are naming schemes which 
identify the things they denote, so that the scope of what counts as 
a 'resource' is limited only by the availability of URI naming 
schemes.

------

Obviously the 'new' wording here at the end is only a suggestion, but 
something like this would serve to explain why the scope of 
"resource" is so open-ended and also, by distinguishing denotation 
from identification (while allowing them to coincide in some cases, 
eg URNs) provides a way to be more precise in architecture/Sweb 
descriptions (eg there can be denotations which do not work through 
identifiers.)

This second version allows the notion of "resource" to be somewhat 
restricted compared to the entire universe of discourse: it really 
does refer to things that can be IDENTIFIED rather than merely 
referred to. This seems to go along with much of what is said about 
URIs and resources in other parts of the document.

However, a substantive question, not about wordsmithing. Do y'all 
want to say that anything that can be *described* using URIs should 
count as a resource? Because that is a larger category than things 
that can be *identified* by a URI scheme.  This point has been made 
in email by others, but it bears repeating. Some URIs (the RDF/OWL 
vocabulary) now have official meanings (lets suppose that those 
meanings are resources) which allow one to write expressions which 
unambiguously refer to things that may not have any URI identifying 
them, and in fact may not even be the kind of things that any URI 
scheme currently in existence would be empowered to identify.  Since 
the process of writing OWL ontologies is so much easier and faster 
than the process of registering new naming schemes, this is likely to 
always be true. So you might want to say that the real definition of 
"resource" ought to be anything that can be uniquely *described* 
using URIs. Then just being directly identified by a URI is like the 
ground case of a potentially very large recursion.

On the other hand, to return to wordsmithing, you might want to 
deliberately NOT say this, because this would require major changes 
to other parts of the document.

Pat

>
>Larry
>--
>http://larry.masinter.net
>
>
>===================================
>
>OLD
>     Resource
>        Anything that has been named or described can be a resource.      ^
>        Familiar examples include an electronic document, an image, a
>        service (e.g., "today's weather report for Los Angeles"), and a
>        collection of other resources. A resource is not necessarily
>        accessible via the Internet; e.g., human beings, corporations, and
>        bound books in a library can also be resources. Likewise, abstract
>        concepts can be resources, such as the operators and operands of a
>        mathematical equation, the types of a relationship (e.g., "parent"
>        or "employee"), or numeric values (e.g., zero, one, and infinity).
>        These things are called resources because they each can be
>        considered a source of supply or support, or an available means,
>        for some system, where such systems may be as diverse as the World
>        Wide Web, a filesystem, an ontological graph, a theorem prover, or
>        some other form of system for the direct or indirect observation
>        and/or manipulation of resources. Note that "supply" is not
>        necessary for a thing to be considered a resource: the ability to
>        simply refer to that thing is often sufficient to support the
>        operation of a given system.
>
>NEW
>    Resource
>        This document doesn't limit the scope of what might be a
>        'resource'; rather, the term 'resource' is used for whatever it
>        is that a Uniform Resource Identifier identifies; each URI scheme
>        defines the range of things that are identified by
>        URIs using that scheme. Commonly, URIs are used to identify
>        Internet accessible objects or services; for example, an electronic
>        document, an image, a service (e.g., "today's weather report for
>        Los Angeles"), a collection of other resources. However,
>        a resource need not be accessible via the Internet; URIs might
>        be used to identify human beings, corporations, bound books in a
>        library, and even abstract concepts.


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Received on Friday, 28 May 2004 12:32:14 UTC

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