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Re: [ontolog-forum] CL, CG, IKL and the relationship between symbols in

To: "Pat Hayes" <phayes@xxxxxxx>
Cc: "[ontolog-forum] " <ontolog-forum@xxxxxxxxxxxxxxxx>
From: "John Black" <JohnBlack@xxxxxxxxxxx>
Date: Sun, 6 Jan 2008 10:13:13 -0500
Message-id: <037e01c85076$a88c7740$6601a8c0@KASHORI001>
I've read some of the references...I'm happy to concede that 'context' may 
be better replaced by several more specific terms, or at least that we 
always make clear that there are many *kinds* of context. And I'll keep 
reading...    (01)

But I'd like to return to one part of this discussion with an example 'from 
the field' rather than my own manufacture. I'd like to get opinions about 
this example as it still troubles me.    (02)

on Sat. Dec. 29, 2007 at 1:04 PM, Pat Hayes wrote:    (03)

> <huge snip>
PH>>>The key point is, what would count as a
>>>'context' for a context-dependent URI?    (04)

In the following example[1], the differing 'contexts' are the different 
web-pages upon which occurrences of a URI appear.    (05)

PH>>> Consider
>>>this scenario. You, sitting at your computer, use a URi to browse an
>>>interesting website, and you send me an email telling me about it and
>>>citing the URI. I then, sitting at my computer, two days later on the
>>>other side of the planet, type that URI into my browser. We expect that
>>>we will see the same website: but what do our two contexts have in
>>>common? It might be almost nothing: the times, places, browsers,
>>>countries, users, OSs, maybe even cultural and linguistic settings, can
>>>be completely different. It is inherent to the Web that the contexts of
>>>publication and of use of a URI can be arbitrarily different and far
>>>apart on every dimension, yet the URI is supposed to retain its meaning.    (06)

This scenario is not applicable here. We need the following scenario. You, 
sitting at your computer, use URI-A to browse to an interesting web-page 
upon which you see a small graphic, retrieved by an occurrence of URI-CD, 
which refers to an assertion that the web-page you are viewing is written in 
valid XHTML 1.0.    (07)

This is URI-CD:  http://www.w3.org/Icons/valid-xhtml10    (08)

What this URI is intended to denote is this assertion (from the W3C help 
page: http://validator.w3.org/docs/help.html) "To show readers that one has 
taken some care to create an interoperable Web page, a "W3C valid" badge may 
be displayed (here, the "valid XHTML 1.0" badge) on any page that 
validates."    (09)

Now you go to URI-B and see that same graphic, because the author of that 
web-page put an occurrence of URI-CD on his page as well. But this 
occurrence of URI-CD is used by the author of URI-B, to refer to his (author 
of URI-B) claim that URI-B (rather than URI-A) is an "interoperable Web 
page".    (010)

My claim is that the referent of each occurrence of this URI 
http://www.w3.org/lcons/valid-xhtml10 is context-dependent upon the web-page 
upon which it appears. In other words it is essentially indexical: it always
refers to an assertion that "THIS page validates", where *this* changes with 
each occurrence.    (011)

Now the strongest objection to this I can see so far is this: The URI 
denotes a single unique assertion as an uninterpreted whole, a black box, so 
to speak. Any further interpretation of that opaque sentence, as an 
assertion of validity, for example, is out of the scope of web-arch 
entirely. The indexical, specifically, is only encountered later, by the 
client or her application. Therefore, the URI denotes the same thing 
everywhere. I'm still thinking about this...    (012)

[big snip about fingerprints]    (013)

PH> No, I think fingerprints don't have referents at
> all. Unless someone invents a 'language of fingerprints', but I haven't
> seen such a thing ever proposed.    (014)

I think this is a bit unfair since you used your rutabaga-reference example. 
Does this imply a 'language of rutabagas'? :-) but no matter.    (015)

PH from another post>>"I can refer to a thing without naming it. We do this 
all the
>>time. For example, I might pick up a vegetable in a supermarket and say to
>>you, "Rutabaga?", using the vegetable itself as the object of my query."    (016)

JB>>So it is with a name (in
>>context) or a URI: The time-varying set of representations of the resource
>>doesn't change, but *what it is* may vary.    (017)

PH> But that is exactly what CL denies about names
> (and the TAG about URIs). Under appropriate http-200 circumstances, a URI
> denotes what it accesses. Which is unique, right?    (018)

I'm claiming that http://www.w3.org/lcons/valid-xhtml10 uniquely accesses a 
small .gif file, but that it denotes an assertion about the the web-page 
upon which each occurrence of the URI is embedded. Furthermore, I say the 
W3C clearly stipulates that it denotes that assertion and not the .gif, in 
spite of REST and TAG, that it has been used successfully to denote it for 
years, without breaking the web, and that its denotation is just as usable 
by machine-processors as by humans, since it may form the basis of a parser 
choice, for example.    (019)

Now are you saying that the CL specification, along with the TAG, specifies 
that names must not refer to such indexical assertions?    (020)

> And under the REST model, a resource (in current jargon: information
> resource) *is* a function from times to webarch:representations. So *what
> it is* cannot vary, by definition, as a basic Web-architecture
> requirement.
> One reaction to this is to denigrate the lack of context-sensitivity in
> current Web communications.    (021)

My objection is subtly different, my objection is that a science of the web 
may show that there are already some kinds of context-sensitivity in current 
Web communications and it is not breaking anything. And this is because some 
kinds of context are not hard to handle. For example, a browser knows what 
web-page it has got, and thus has an easy time resolving the indexical.    (022)

> But another is to simply accept that the open, global nature of the Web
> makes it essential to presume that Web names - URIreferences - are
> transparent (every occurrence of them have the same meaning) and to write
> ontologies accordingly. The cost of the former - a complete re-design of
> the entire apparatus of Web logic along lines that are yet to be
> researched - seems to greatly exceed that of the latter, which really
> amounts simply to following a certain discipline in inventing URI
> references. At any rate, like it or not, this is how the SWeb is evolving.
> Pat    (023)

1. http://kashori.com/2006/07/problems-identifying-information.html    (024)

John Black
www.kashori.com    (025)

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