- From: Harry Halpin <hhalpin@ibiblio.org>
- Date: Fri, 15 Oct 2004 02:27:35 -0400 (EDT)
- To: www-tag@w3.org
This notion of "information resource" is definitely tricky, but I concur as an outside observer that TAG is on the right track. I'm still not sure if this is really testable in all cases, but it seems to lie on some pretty good common-sense intuitions. I guess the test would be "If this *thing* is represented, is the representation still *this thing*, and not a *representation of this this thing*"? If you take a picture of a dog, you clearly a "representation of a dog", not *an actual dog*. If you have my medical record and take it from a piece of paper and put in into some database, then general an XML file from that database that flies across the Web, that XML file is *my medical record* in the same sense that the original paper version is and not *a representation of my medical record*. In fact, the word *representation of my medical record* doesn't even make much sense, does it? By hook or by crook matters of reference are being dragged into the TAG. >From the current definition of "information resource", all "essential properties" are conveyed in the digital message. The question is then "what is essential?" A real life shaggy dog has many essential properties that are resistant to being made part of a digital representation, such as a smell. However, is the smell "essential", and is that adjective by nature not subjective? Who dictates what is essential? Any abstraction of my real life shaggy dog would doubtless lead many properties behind that *someone* could judge to be essential. But in domain of medical records, there are standard things that are measured (like heartbeat) and written down, and *all of this information* can be conveyed in message (in XML, RDF, binary). Things like the type of paper the record is on or the expression on the doctors face as they wrote down the heartbeat are inessential, because they are judged not to be part of the medical record. The reason all a medical record can be conveyed as an information resource while a dog cannot is because a medical record is *already abstract information* while a real-life shaggy dog is *not abstract* at all. The key notion seems to be a *level of abstraction*, and it certainly seems somethings that are abstract (like numbers) are much more amendable to being digital (and thus being conveyed on the Web) than things like smell or the gleam in someone's eye. Now, there are border-line cases - what about "the class of all tigers?" It's abstract - but what are it's essential properties? Being a feline and a quadriped? But as Searle notes, a tiger with a leg missing is after all, still a tiger. It appears the idea of the "class of all tigers" does not exist at suitable level of abstraction for description of its essential properites, much less digitization of its properties, - and so the "class of all tigers" is not an informaton resource. Correct? I mean, where's the test? So, it appears an information resource is something whose essential properties can be conveyed, as a message, because the thing being conveyed exists at a level of abstraction where it can be digitized in its entirety. This has ramifications since such a thing can be realized in multiple formats. Your real-life dog can only be represented by that thing that *actually* smells, the class of all dogs can only be represented by the actual class of all dogs (existing, existed, and perhaps to exist or imagined) and also can't be a resource. But an instance of a medical record, being basically numbers and strings, is just the right level of abstraction and digitization to be an information resource. Am I correct? I might add it appears we're all using "information" in a Dretskian sense, not a Shannon sense. If I get a spare day or two in the next week I'll write a quick squib on various stabs people have had at defining information, and post it to both www-tag and xml-dev since this notion keeps returning. I would recommend reading D. Israel's "What is Information" and F. Dretske's "Precis to Knowledge and the Flow of Information" for further, and perhaps useful, background information. My two cents, Harry On Fri, 15 Oct 2004, Chris Lilley wrote: > > On Thursday, October 14, 2004, 9:51:39 PM, noah wrote: > > nuic> Perhaps it's worth noting that our current editors draft says [1] > > nuic> TRUE per Basel Definition: "The distinguishing > nuic> characteristic of these [information] resources is that > nuic> all of their essential characteristics can be conveyed in a message." > > nuic> but it does NOT say the converse: > > nuic> FALSE per Basel Definition: "A non-information resource is distinguished > nuic> by the fact that none of its state can be conveyed in a message." > > Yes, exactly. And that is good and I am comfortable with it. > > nuic> We shouldn't be surprised that there is some machine-representable state > nuic> for a real live shaggy dog. > > > I'm not. But (see earlier threads on testability) saying that an IR is > any resource for which there exists any information whatsoever is > equivalent to saying IR == resource, thus making it a useless and > meaningless term. > > nuic> We might choose to expose its temperature or > nuic> its weight, for example. The distinction drawn in Basel is that dogs are > nuic> interestingly different from information resources because there exist > nuic> essential aspects of the dog that are not conveyable in a machine-readable > nuic> way. > > Yes and this was a distinction that I was happy to see made, and stopped > opposing the term IR because it was now both useful and testable. > > nuic> Noah > > nuic> [1] http://www.w3.org/2001/tag/webarch/#id-resources (I don't think I have > nuic> a stable link in date space for this, unfortunately) > > nuic> -------------------------------------- > nuic> Noah Mendelsohn > nuic> IBM Corporation > nuic> One Rogers Street > nuic> Cambridge, MA 02142 > nuic> 1-617-693-4036 > nuic> -------------------------------------- > > > > > > > > Harry Halpin Informatics, University of Edinburgh http://www.ibiblio.org/hhalpin
Received on Friday, 15 October 2004 06:27:36 UTC