- From: Larry Masinter <masinter@adobe.com>
- Date: Mon, 13 Jul 2009 09:04:33 -0700
- To: David Booth <david@dbooth.org>, "Sean B. Palmer" <sean@miscoranda.com>
- CC: "www-tag@w3.org" <www-tag@w3.org>
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 16:05:19 UTC