- From: David Booth <david@dbooth.org>
- Date: Mon, 13 Jul 2009 13:37:15 -0400
- To: Larry Masinter <masinter@adobe.com>
- Cc: "Sean B. Palmer" <sean@miscoranda.com>, "www-tag@w3.org" <www-tag@w3.org>
Hi Larry, I think we're talking about two different things here: the proposed tdb: scheme, and the definition of "information resource". I don't think I can offer the TAG specific input on what should be considered a higher priority than what else, but in general I would say: - URIs are the foundation of the Web, and the network effect is important, hence the proliferation of URI schemes is important to prevent. - Consternation over the definition of "information resource" (and the related httpRange-14 issue) has been a persistent thorn for a long time, consuming much aggregate brain power. It would be nice to lay it to rest (if possible). David Booth On Mon, 2009-07-13 at 09:04 -0700, Larry Masinter wrote: > I've updated the "tdb" document (removing duri) > as a contribution to the puzzle of > "URI for abstract concept": > > http://www.ietf.org/internet-drafts/draft-masinter-dated-uri-06.txt > > It provides a way of creating a URI that can identify > anything that you can describe. > > I don't want to start the meta-discussion on the www-tag > mailing list, but I would appreciate (private, or cc'd to > www-archive only if you prefer), reasons why you think > resolving this is of higher priority than the other > topics the TAG is now considering. > > For my part (and I think I'm an outlier on the TAG alas) > I am not at all convinced that this topic meets all of the > criteria I have for what I think should be high priority > for the tag: something we can resolve, will likely have an > effect on the participants in Web architecture, in which > the TAG has expertise, is relevant to the ongoing > important work of W3C groups, is not better addressed > by specific working groups chartered for the purpose, > ... > > I'm not particularly happy (personally) with what the > AWWW document says about "information resources", but > why is it important for the TAG to spend a lot of time > fixing? > > Thanks, > > Larry > -- > http://larry.masinter.net > > > > -----Original Message----- > From: www-tag-request@w3.org [mailto:www-tag-request@w3.org] On Behalf Of David Booth > Sent: Sunday, July 12, 2009 7:25 PM > To: Sean B. Palmer > Cc: www-tag@w3.org > Subject: Proposed AWWW erratum on "information resources" [was Re: Fwd: Splitting vs. Interpreting] > > On Thu, 2009-06-18 at 17:34 +0100, Sean B. Palmer wrote: > > On Thu, Jun 18, 2009 at 7:45 AM, David Booth wrote: > > > > > The flaw that I think should be fixed is the definition of "information > > > resource" (IR) in the AWWW: > > > http://www.w3.org/TR/webarch/#id-resources > > > "all of their essential characteristics can be conveyed in a message". > > > > What would you propose for an erratum? > > Okay, since you asked . . . ;) I'd suggest the following changes. > > 1. The first three paragraphs of section 2.2 currently read: > http://www.w3.org/TR/webarch/#id-resources > [[ > By design a URI identifies one resource. We do not limit the scope of > what might be a resource. The term "resource" is used in a general sense > for whatever might be identified by a URI. It is conventional on the > hypertext Web to describe Web pages, images, product catalogs, etc. as > “resources”. The distinguishing characteristic of these resources is > that all of their essential characteristics can be conveyed in a > message. We identify this set as “information resources.” > > This document is an example of an information resource. It consists of > words and punctuation symbols and graphics and other artifacts that can > be encoded, with varying degrees of fidelity, into a sequence of bits. > There is nothing about the essential information content of this > document that cannot in principle be transfered in a message. In the > case of this document, the message payload is the representation of this > document. > > However, our use of the term resource is intentionally more broad. Other > things, such as cars and dogs (and, if you've printed this document on > physical sheets of paper, the artifact that you are holding in your > hand), are resources too. They are not information resources, however, > because their essence is not information. Although it is possible to > describe a great many things about a car or a dog in a sequence of bits, > the sum of those things will invariably be an approximation of the > essential character of the resource. > ]] > > I suggest changing the above paragraphs to: > [[ > By design a URI identifies one resource. The term "resource" is used in > a general sense for whatever might be identified by a URI. We do not > limit the scope of what might be a resource. A resource could be > anything that one may wish to identify -- physical, conceptual, real or > imaginary. > > An "information resource" is any resource that plays a role in the > hypertext Web by producing "representations"[link to definition in sec > 3.2] in response to Web requests. Web pages, images, product catalogs > and other things that are made available on the Web are all information > resources. Some information resources, such as static web pages, may > change very little or not at all over time. Others, such as one that > displays the current weather report for Oaxaca, may vary frequently. > Similarly, some information resources, such as an interactive travel > booking site, may vary their representations depending on their > requests. Others, such as simple Web pages, may not. Conceptually one > can think of an information resource as a function from time and request > to representation. > > Ambiguity of Resource Identity > > Although a URI is intended to identify one resource, and ambiguity about > the identity of that resource should be avoided to the extent possible, > ultimately ambiguity is in the eye -- or the application -- of the > beholder. Because anything can be a resource, what one party considers > a single resource (perhaps having multiple aspects) another party making > finer distinctions might consider multiple resources that should have > distinct URIs. > > For example, the content of a book may be placed on the web and > identified by a particular URI. Many parties will have no need to > distinguish between the web page that provides the content of the book > and the content of the book as an artistic work that is subject to > copyright law. Depending on one's perspective (or application) this may > be viewed as a case in which the URI unambiguously identifies a resource > that has multiple aspects or as a case of ambiguity, in which the > artistic work and the web page are each deserving of their own distinct > URIs. > > Resources whose essential characteristics can be conveyed in message are > good candidates for being considered information resources. Other > things, such as cars and people are less good, because some applications > are likely to find them ambiguous. For example, if the same URI is used > to directly identify both a person and a Web page -- an information > resource -- an application that records the creation dates of people and > Web pages may find this resource ambiguous, because it cannot > distinguish between the creation date of the person and the creation > date of the web page. This ambiguity would be avoided by giving the > person and the web page separate URIs. On the other hand, the use of > two separate URIs may impart a cost to other applications that have no > need to distinguish between the person and the Web page, because it > requires these applications to recognize two URIs that those > applications consider equivalent. > ]] > > 2. The current definition of "representation" reads: > http://www.w3.org/TR/webarch/#internet-media-type > [[ > A representation is data that encodes information about resource state. > Representations do not necessarily describe the resource, or portray a > likeness of the resource, or represent the resource in other senses of > the word "represent". > ]] > > I suggest changing this to: > [[ > A representation is a response, from an information resource, that > encodes information reflecting that information resource's state. > Representations do not necessarily describe the information resource, or > portray a likeness of the resource, or represent the resource in other > senses of the word "represent". Only an information resource can have > representations in the sense used herein. > ]] > > 3. In addition to the above changes, there are many instances of the > word "resource" that should be changed to "information resource", > because the context only applies to information resources -- not > resources in general. > > -- David Booth, Ph.D. Cleveland Clinic (contractor) Opinions expressed herein are those of the author and do not necessarily reflect those of Cleveland Clinic.
Received on Monday, 13 July 2009 17:37:52 UTC