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[Fwd: Re: WG: homonym URIs (Re: What if an URI also is a URL)]

From: Alejandro Cabral <alejandro.cabral@oracle.com>
Date: Mon, 25 Jun 2007 17:52:10 -0300
Message-ID: <46802AFA.6010009@oracle.com>
To: semantic-web@w3.org
       I am sorry to pick up this thread so late, I was out in the road 
for two weeks and had quite a few emails to answer before this one. I 
would recommend reading about "edenic languages" (U. Eco I believe) to 
understand the relation between symbols and actual meanings. Then, 
Peirce would of course be an appropiate author. Hereīs a nice graph 
about itīs first trichotomy (Iīm sorry itīs in Spanish, I didnīt find it 
in English): 
http://www.ugr.es/~mcaceres/Entretextos/entre6/Figura%204a.png. I think 
it can help better understand how to attach a certain something (through 
a symbol) to a certain other something (an object).

Thereīs also a note to be made on "knowledge encyclopaedias", meaning 
what each individual/machine knows (regarding itīs unique experience 
within itīs context/world) and what they share (probably they both know 
i.e. what a "pebble" is, though they may not share the same symbols).

The multi-layer semantic data model (Sieber-Kovács), may shed some light 
over this: understanding these three basic levels 
(form-representatives-meaning) we should be able to apply this model to 
the semantic web construct when it comes to assigning a certain "anchor" 
to an object (a symbol of course). In order to get to the level the 
semantic web needs (the meaning lvl that is) to function as we intend it 
to, we must first understand the first two levels and their relations. 
Thatīs exactly where we must set the right anchors (transparency is key).

So, the right question I think would be: in which lvl and layer do we 
place URIs?


Tanja Sieber wrote:
> Alejo,
> could you do me a favour and place a statement in this on-going discussion
> involving our developped semantic data model referring to Peirce. It's more
> worth that I will write above it again by myself:-)
> Tanja
> -----Ursprüngliche Nachricht-----
> Von: semantic-web-request@w3.org [mailto:semantic-web-request@w3.org]Im
> Auftrag von Ian Davis
> Gesendet: Donnerstag, 14. Juni 2007 00:58
> An: John Black
> Cc: Pat Hayes; Sandro Hawke; semantic-web@w3.org
> Betreff: Re: homonym URIs (Re: What if an URI also is a URL)
> On 13/06/2007 14:10, John Black wrote:
>> Please forgive me, Ian, I'm going to highjack this for myself.
> By all means :)
> I wrote:
>>> Out of interest how do you attach the English word "Venus" to the
>>> physical body that you are referring to?
> To which you part of your reply was:
>> 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.
> This is what I expect and it makes its point very well. My question was
> somewhat rhetorical to test whether I understood the debate adequately.
> I think I do now.
>> 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."
> This is the bit I don't understand. I'm not a logician nor a philosopher
> so I'm applying the little common sense I have to this problem. It seems
> to me that there is no difference here between the symbol
> "http://example.com/venus" and the symbol "venus" (being the word I
> would utter in conversation). Neither can be attached to the physical
> object that they refer to. However they can both be understood by
> relating them to other symbols.
> In my naive view of human cognition, I imagine that you and I can
> negotiate a shared meaning of a symbol by relating them to many other
> symbols to the degree that really only a single thing can be the
> referent. My conceptual graph of relations between symbols is isomorphic
> to yours so the thing at the heart of that graph must be the same as yours.
> Clearly this is easier when you are able to indicate the referent of a
> symbol by pointing to it, e.g. an apple on a tree. However in the
> semantic web we only have a single sense with which to relate things
> together. It's like sharing knowledge with someone when neither of you
> can see, taste, feel or move.
>> 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 background.
> OK, this is new stuff for me, but it seems to me that it's like pointing
> to the apple in my example above.
>> 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.?
> Isn't that where humans come in? Your RDF states that a particular URI,
> when dereferenced using HTTP, provides a depiction of an apple. I try
> that, see an apple and conclude that I now understand the meaning of
> your URI (it may take a while if I don't understand your property).
> The following metaphor came to me while writing the above about having
> only a single sense. I wonder if it helps illuminate why I think the
> semantic _web_ is different to the world of semantics that came before:
> Imagine you and a stranger can only communicate through the use of
> coloured pebbles that you may place in various arrangements. Suppose
> this stranger arranges a crimson pebble between a yellow pebble and a
> blue one. Next they place another crimson pebble next to the blue one
> and a white one next to the new crimson one. Then they place a brown
> pebble next to the blue one and a grey one beside that. Finally they
> place a green pebble and a black one with yet another crimson pebble
> between them.
> You start to see a pattern forming. Somehow the crimson pebbles link the
> other pebbles together and you suspect it represents some common
> relationship. However, since you can only communicate in coloured
> pebbles you can never relate that to the rest of the world.
> Now, suppose you learn that you can turn the pebbles over. You turn the
> yellow pebble over and discover a picture of a young Elvis painted on
> it. You turn the white one over and discover a picture of an older
> Elvis. You turn the blue pebble over and there's nothing on the other
> side. The same is true for the crimson pebble. When you turn the grey
> pebble over you see the number 1935 inscribed on it.
> Now you turn to the second arrangement of pebbles. Under the green one
> is a picture of Bill Haley. The crimson one is blank, as is the black one.
> Perhaps you might infer that the red pebble somehow denotes "picture",
> although with this limited evidence there are many other possible
> explanations. The more arrangements of crimson pebbles touching pebbles
> with pictures on the back you see, the more confidence you might gain
> that the crimson pebble denotes "picture". Even more so if you have no
> contradictory evidence. At some point you may even infer that the blue
> pebble denotes Elvis Presley.
> Turning the pebbles over is grounding it in the real world; in your
> human experience.
> In the Semantic Web the equivilent of turning the pebbles over is
> dereferencing a URI. For HTTP URIs, we perform a GET. A human can do it
> to discover what a URI denotes and by looking at lots of these patterns
> they can gain confidence in their interpretations of the URIs that
> denote the relationships between these things.
> That's how I see the Semantic Web.
> Ian
> ____________
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Received on Monday, 25 June 2007 20:53:02 UTC

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