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Re: Information resources

From: Dan Connolly <connolly@w3.org>
Date: 28 Jul 2003 18:27:18 -0500
To: Tim Bray <tbray@textuality.com>
Cc: WWW-Tag <www-tag@w3.org>
Message-Id: <1059434838.16953.715.camel@dirk.dm93.org>

On Mon, 2003-07-28 at 16:53, Tim Bray wrote:
> Today in the TAG teleconference I took an action item to draft some 
> language about resources and "Information Resources".

Thanks for starting/keeping the ball rolling...

> Many existing Web servers and clients (for example web browsers) do not 
> have any notion of what the Resource identified by a URI is.  However, 
> humans and Semantic Web software are strongly concerned with this issue. 
>   Some resources are perceived as falling into a class called 
> "Information Resources".  That is to say, they are on-line units of 
> electronic information or service.  Examples would include a photograph, 
> a news story, and a weather forecast for Oaxaca.  Other resources named 
> by URIs may exist entirely apart from the Web.

Hmm... that seems contradictory; I'd prefer to leave
"entirely apart from the Web" out of it...

>   Examples include an 
> edition of some book identified by urn:isbn:0-395-36341-1, a person 
> identified in an RDF assertion using http://example.com/foaf#Dan, and an 
> XML namespace such as http://www.w3.org/1999/02/22-rdf-syntax-ns#.  The 
> Web may be used to obtain representations of both kinds of resources.

Hmm... I thought what distinguished information resources from
resources in general is that only information resources have
representations (in the webarch sense).

e.g. take http://example.com/foaf#Dan none of the
deployed/specified infrastructure provides a way get a
representation of that resource; you can only get a representation
of http://example.com/foaf.

As MarkB put it...

  I'd say that a URI was "Web resolvable" if one could build a
  HTTP proxy to resolve it.
  -- http://www.w3.org/mid/20030719230728.G4241@www.markbaker.ca


Let's see... didn't we just about settle on some specific
wording in Vancouver? Here's a suggestion from timbl...

[[
URIs identify resources. A resource can be be anything. Certain
resources are information resources, which convey information. These are
termed *information resources*. Much of this document discusses
information resources, often using the term resource.

An information resource is *on the Web* when it can be accessed in
practice.

When a representation of one information resource refers to another
information resource with a URI, a *link* is formed between the two
resources. The networked information system is built of linked
resources, and the large-scale effect is a shared information space.
]]

 -- http://www.w3.org/2001/tag/webarch/tim.html
Wed, 23 Jul 2003 15:34:19 GMT

Hmm... no, that has some odd bits too.

In trying to draft a replacement, I see that
that 'representation' is used in the intro without
a nearby definition...

  In the travel scenario, Dan's user agent uses the URI to request
  a representation of the identified resource.

I don't have a proposed fix for that just now... it's
somewhat beside the point, in any case...

Back to the point, I'd like to chage

  The page may include links to other information (i.e., more
  URIs) allowing Dan to start the cycle again.

to

  The page includes links to other information that allows
  Dan to start the cycle again. We discuss links further
  in section 2. Identification and Resources.

then, under 2. Identification and Resources,
after
"... what motivates global naming in Web Architecture.":


  When Dan found http://weather.example.com/oaxaca in the magazine,
  he inferred that it was *on the Web*; that is, it has a representation
  available, barring network failures, access policies, and such.
  While URIs can, in general, be used to refer to any sort of
  resource, the case of an *information resource*, that is, one
  for which Web protocols provide representations, is particularly
  relevant to the structure of the Web: a *link* is the use of a URI
  in the representation of an information resource refer to
  another resource. The large-scale effect of the use of these links
  is a shared information space. The value of the Web
  grows exponentially as a function of the number of linked
  resources (the "network effect").


-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Monday, 28 July 2003 19:27:20 GMT

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