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Re: Social meaning discussion 6th March

From: Tim Berners-Lee <timbl@w3.org>
Date: Tue, 04 Mar 2003 08:11:45 -0500
Message-ID: <3E64A611.3020303@w3.org>
To: pat hayes <phayes@ai.uwf.edu>
CC: w3c-rdfcore-wg@w3.org

Pat, I think I agree with you more than you agree with me.
Your message
http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2003Feb/0164.html
I thought was a good summary of the difference between the sorts
of meaning and the imporatance that any "social" meaning is consistent
with the formal meaning.

But below you seem to take a rather extreme view.
I suppose it shows the differences between our backgrounds.


pat hayes wrote:

>> I am concerned that you have thrown out the baby with the bathwater.
>> And still left some bathwater. ;-)
>> Our views do seem rather different
>>
>> What is required, and easy, is to say what an RDF document means.
>
>
> Well, doesn't the MT do this already?
>
>> What is not required and a bad idea is to explain how to use it.
>>
>> 1. The meaning of an RDF document is that of the statements.
>> 2. The meaning of the statement is defined by the definition
>
>
> ?What is a definition?

A definition is a text which describes the meaning of a term..

For example, http://www.w3.org/TR/1999/REC-rdf-syntax-19990222/#property
is (part of) an english definition of a rdf:Property.

I know its a bit ofashock, but we are not being formal here. This definitoin
of property is a rough and ready english definition. But we get by with it
and the rest of the stuff about predicates in the document.

>
>> of the predicate, as applying to the subject and object identified by
>
>
> ?How do the subject and object identify things?

Um.. by using a URI, where sender and receiver share
information which restricts the assication of the URI to one thing
(or one thing withiin a given shared context).
I am not sure what level of answer you are looking for here.

Statements which restrct interpretations such that
within the domain of discourse, for any intepretation,
any things identified by the URI are equivalent?

>
> Neither of these are easy questions to answer and neither of them has 
> an answer in the current spec.

No, that's good, because the questoin of what is identified by a URI
is dealt with in URI spec and associated specs.

The only question that RDF has to answer (not as part of
itself, but as part of a duty delegated from the URI spec) is to
show how, when the URI
is an identifier within an rdf document  (a la foo.rdf#bar), to show how 
RDF allows
the set of things which a URI might by identified to be restricted by
RDF statements about that thing, or as we say in english, how RDF
documents can describe things.


>
>>  the
>>  definition of the subject and object terms.
>>
>> That then hands off to the relevant specs the right and the duty to
>> define their bit.
>>
>> Tim
>> sans chapeau.
>>
>> Brian McBride wrote:
>>
>>> Sans chapeau:
>>>
>>> My bath time this morning was spent thinking about social meaning. I 
>>> came to the conclusion that 'meaning' is a difficult and slippery a 
>>> concept that we should try to stay away from, sticking to things 
>>> that are more concrete.  We should leave talk about 'meaning' to the 
>>> philosophers.
>>
>>
>> There we differ.  For me, the meaning of a bit-field or a docuemnt or 
>> a packet
>> or a message is what specs are for.
>
>
> Where does any spec for packets, mime type, etc., ever refer to 
> meaning? The very idea of  of 'bit' is rooted in a meaning-free notion 
> of 'information', for example.

@@@@
Interrupted by face-face encounter.


>
>>> Perhaps we can get all we need by describing intended use.
>>
>>
>> That is where you start getting into questionable stuff, necessarily
>> slanting the use of RDF some way.
>>
>> If  my:car :color :blue means that my car is colored blue, that
>> is what it means, quite independent of context.
>> The concept of  something having a given color is
>> defined (and only defined) by the definition of color
>
>
> Bad example, as color terms don't have definitions.

They do. Casesium red is the sprectrum of an excited Caesium atom.
Some are vauge -- red is a color which has predominatlylonger wavelengths.


>
>> and my:car only serves to idetify the car
>
>
> How does a uriref identify a car? (Genuine question, not rhetorical :) 

Notionally, the URIref identifies the car so long as everyone who uses
it does soconsistently with it identifying the car.

Specifically and practically, the semnatic web protocol is that
a web page in RDF foo.rdf  has a description of something
of type Car and typically giving a country code and plate number
as property values.



>
>
> Pat
>
>
Received on Tuesday, 4 March 2003 08:12:15 EST

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