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Re: homonym URIs (Re: What if an URI also is a URL)

From: John Black <JohnBlack@kashori.com>
Date: Wed, 13 Jun 2007 09:10:41 -0400
Message-ID: <1aeb01c7adbc$3eb16ae0$6601a8c0@KASHORI001>
To: "Ian Davis" <lists@iandavis.com>, "Pat Hayes" <phayes@ihmc.us>
Cc: "Sandro Hawke" <sandro@w3.org>, <semantic-web@w3.org>

Please forgive me, Ian, I'm going to highjack this for myself.

Ian Davis wrote:
> On 12/06/2007 17:21, Pat Hayes wrote:
>> You are begging the question. Suppose an ontology asserts
>> ex:Venus rdf:type ex:AstronomicalBody .
>> Now, what ties that object URI to the actual concept of being an 
>> astronomical body?

This ambiguity between concept and object is one of the most common I see in 
semantic web discussions. But surely the two are different.
"The planet Venus circles the sun" - sounds plausible
"The concept Venus circles the sun" - huh?

Also, at least for terrestrial objects, it is actually possible to attach a 
URI to the referent it denotes.
see this image: 
And real world examples of this are bar codes on products, which denote 
classes of things, and bar codes on special delivery packages which denote 
individual shipments. The reason this works is that by placing a symbol 
directly on an object, you enable a shared experience or "perception" of 
that package among all those agents that encounter it.

>> And so on for all the other URIs in all the other OWL/RDF ontologies. The 
>> best you can do is to appeal to the power of model theory to sufficiently 
>> constrain the interpretations of the entire global Web of formalized 
>> information. But that argument from Herbrand's theorem (basically, if it 
>> has a model at all then it has one made entirely of symbols) applies just 
>> as well no matter how large the ontology is.
> Out of interest how do you attach the English word "Venus" to the physical 
> body that you are referring to?

This is the question. And the short answer is, you don't. That's the point. 
That isn't how it works, in general. In natural language, a reference from a 
symbol such as "Venus" to the planet Venus is based on the shared experience 
of the speaker and hearer, or writer and reader. In speech especially there 
is often a bit of a dance, or at least a kind of a handshake, between the 
sender and receiver to establish and maintain a reference.

"I think Venus is wonderful!"
"Yeah, I just love her backhand."
"No. I meant the planet, not the tennis player"
"Ah, the evening star, I'll never forget the night my mother pointed that 
out to me and told me it was actually a planet named Venus."

When I write the word Venus, I do it expecting you, my readers, to have had 
similar experiences to me. I expect you studied the planets in first grade, 
have access to WikiPedia, can clearly see the sky, that some trusted elder 
spoke the word "Venus" and pointed your attention to a bright light in the 
sky, etc., etc. Also, if I know that there may be confusion, because the 
word can be ambiguous, I may add to the dance with a little jig, as in, "I 
think Venus, the planet, is wonderful." If I have already established the 
context, however, I may count on you to disambiguate it yourself. In a 
report about the planets of our solar system, I expect you to infer yourself 
that I mean Venus to refer to the planet, not the tennis player.

Restoring some of Pat's remarks, "The only way out of this is to somewhere 
appeal to a use of the symbolic names - in this case, the IRIs or URIrefs - 
outside the formalism itself, a use that somehow 'anchors' or 'grounds' 
them to the real world they are supposed to refer to."

What he is calling "...outside the formalism itself...", I am referring to 
as shared experiences, following John Dewey, and which Herbert Clark calls 
common ground, Kripke calls a name baptism, and Searle refers to as the 

So the big, big question, IMHO, for the semantic web is this. What can be 
done to mimic, in some minimal, but sufficient way, using existing web 
technologies, in a way that machines can utilize if possible, the grounding 
of URI in something outside the formalism of RDF/OWL/etc.?


> Ian
> -- 
> work - http://www.talis.com/platform
> play - http://iandavis.com/blog
> callto:ian_davis
Received on Wednesday, 13 June 2007 13:12:01 UTC

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