W3C home > Mailing lists > Public > www-rdf-logic@w3.org > August 2001

SW, meaning and reference

From: Dan Brickley <danbri@w3.org>
Date: Fri, 31 Aug 2001 15:00:53 -0400 (EDT)
To: pat hayes <phayes@ai.uwf.edu>
cc: <www-rdf-logic@w3.org>
Message-ID: <Pine.LNX.4.30.0108311442060.17596-100000@tux.w3.org>

(happily removing QNames from Subject: line)

On Fri, 31 Aug 2001, pat hayes wrote:

> >On Thu, 30 Aug 2001, pat hayes wrote:
> >
> > > [...] Really pinning down actual *reference* to *real things* is a
> > > very, very  tricky business, one that is way beyond the ability of
> > > current semantic theories to analyse, and therefore probably best
> > > left aside for now in these discussions.
> >
> >Amen! This is however something that Semantic Web (via our use of both
> >URIs and of RDF descriptions for identification) will need to
> >engage with at some point.
> I agree, but be ready for having to do some hard, basic (and
> therefore slow) research. New syntaxes are easy, and model theories
> can be churned out to fit most any reasonable intuitions about
> consistency, but reference is harder.

Yes... reference is far murkier, theoretically. And imho likely to stay
that way. The precision that we achieve through DAML+OIL-style formalism
will always be in tension with the unavoidably fuzzier aspects of meaning
associated with our notion(s) of reference. (which is fine; interesting even...)

> > I do think that the 'reference' aspect to
> > 'meaning' is something we'll need to deal with if SW is to fulfill
> > expectations w.r.t. ecommerce etc.
> Ecommerce only requires something that works pragmatically.

Sure; I don't mean to suggest that the SW will be paralysed because nobody
has perfected a formalisation of how URIs denote. People will find way to
build systems that buy and sell (and lie and cheat) regardless.

> I'm sure there are several ways to make the SW work well enough for ecommerce,
> but if the $$ have to wait for a universal theory of reference, the
> investors had better be ready to take a very long view.

Wiser to give up on trying; everything I've read on theory of reference
inclines me to think that the only way to succeed is to give up.

Stephen Stich writes (imho) quite persuasively on this...

(not quite the excerpt I was looking for, but all that Google could find...)

Before I could start on that project, however, there was a prior question
to be confronted. If the goal was to produce a correct theory of reference, I would have to
get clear on what it is that makes a theory of reference correct or
incorrect. What exactly are the facts that a correct theory of reference is supposed
to capture? And how can we find out whether a theory has succeeded in
capturing those facts?


That argument starts with a hunch, albeit a widely shared one. While there
are lots of theories of reference on the market  these days, my hunch is
that the accounts that do the best job at capturing
people's relatively firm and stable intuitions about reference are not  those
that follow the path staked out by Ramsey and Lewis, but rather those that
tell what Lycan calls a "causal-historical" story. The basic idea
of these theories, as we saw earlier, is that words get linked to things
in the world via causal-historical chains. The first step in creating such
a chain is a "grounding" or a "reference fixing" - an
event or process (or, more commonly, an array of such events or processes)
in which a term is introduced into a language to designate an object or
a kind of objects. Following this there is a series (often a very long
of reference preserving transmissions, in which the term is passed from
one user to another, preserving the reference that was fixed when the term
was introduced. But, of course, not just any way of introducing a term
into a language will count as grounding the term on a particular object or kind
of objects, and not just any way of passing a term from one user to
another will count as a reference preserving transmission. The legitimate
groundings and transmissions will be those embedded in causal-historical chains that
are sanctioned by intuition. When one looks carefully at the class of
groundings and the class of transmissions that pass this test, however, it appears
that in each class the allowable events are a mixed bag having at best a
loosely knit fabric of family resemblances to tie them together.

While I could imagine someone setting out to redescribe URIs in terms of
an initial 'GroundingEvent' or 'NamingEvent', and (say) a
causal-historical account of naming, I wouldn't join a W3C Working Group
attempting such a thing if you paid me! Meanwhile, as you say, ecommerce
will surely happen regardless. So I'm not spreading doom and gloom; just
claiming that reference is the weak spot when we come to formalise the
'semantic' web.

Received on Friday, 31 August 2001 15:00:54 UTC

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