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Re: context (comments on http://www.w3.org/TR/2002/WD-rdf-schema-20021112/)

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Wed, 04 Dec 2002 17:45:49 +0000
Message-Id: <5.1.0.14.0.20021204173943.03292a88@0-mail-1.hpl.hp.com>
To: "Richard H. McCullough" <rhm@cdepot.net>, "pat hayes" <phayes@ai.uwf.edu>
Cc: <www-rdf-comments@w3.org>

Gentlemen,

The RDFCore WG considered the issue of contexts

   http://www.w3.org/2000/03/rdf-tracking/#rdfms-contexts

and decided to postpone it for consideration by a future WG.

I don't want to discourage you guys discussing it further, but I suggest 
holding that discussion on another list, possibly www-rdf-interest@w3.org.

I'd like to keep this list focused on discussion relevant to the current 
round of specs.

Brian



At 09:09 04/12/2002 -0800, Richard H. McCullough wrote:
>My comments are interspersed below, prefixed with #####.
>============
>Dick McCullough
><http://rhm.cdepot.net/>knowledge := man do identify od existent done
>knowledge haspart proposition list
>----- Original Message -----
>From: <mailto:phayes@ai.uwf.edu>pat hayes
>To: <mailto:rhm@cdepot.net>Richard H. McCullough
>Cc: <mailto:bwm@hplb.hpl.hp.com>Brian McBride ; 
><mailto:www-rdf-comments@w3.org>www-rdf-comments@w3.org
>Sent: Tuesday, December 03, 2002 2:22 PM
>Subject: Re: context (comments on 
><http://www.w3.org/TR/2002/WD-rdf-schema-20021112/>http://www.w3.org/TR/2002/WD-rdf-schema-20021112/)
>
>>I have consistently used the same definition of context 
>>(<http://rhm.cdepot.net/doc/KEtutorial.txt>http://rhm.cdepot.net/doc/KEtutorial.txt) 
>>
>>     space = where action occurs
>>+  time = when action occurs
>>+  view = proposition list which captures prior knowledge
>Well, OK, but that is a very odd collection of disparate kinds of 
>thing,  seems to me, which have very little in common (and very little in 
>common with the other uses of that word in other, er, contexts). What is 
>the connection between actions and propositions, for example?
>##### Here's a proposition (in KR)
>#####    at space=s, time=t, view=v  { Joe do hit od the ball done }
>##### This proposition characterizes an action, "hit".  It specifies the 
>subject, "Joe", the object, "the ball", and the context, s/t/v.
>##### The meaning of this proposition, the things it denotes in reality, 
>is clearly dependent upon the context.  For example: compare space=the 
>local sandlot and space=a major league baseball stadium; compare time=4 
>December 2002 and time=15 May 1941; compare view={Joe is Joe Doe} and 
>view={Joe is Joe DiMaggio}.  (Of course, view should be a name, and might 
>include many other propositions in addition to the identity/alias given here.)
>And in the first two cases, where are the spatiotemporal boundaries drawn? 
>Take this email conversation that we are having and other people are maybe 
>reading: what is the space where that action is occurring?
>##### at space=Pioneer California { I do write od this email done }
>##### at space=your office in Florida { you do read od this email done }
>##### If you want to consider the complex action/event of all the people 
>reading this email, space=union of all their locations.
>
>>Depending of the context of the discussion, I sometimes emphasized one of 
>>space/time/view,
>>but my definition has not changed.
>>
>>I am fully aware that others do not agree on a definition of 
>>context.  You and I attended the same
>>Context Symposium at MIT in 1997.
>I recall. Things havn't gotten any better, you know.
>
>But more seriously, we can't be expected to use *your* definition of 
>context in a language intended for general Web use all over the planet.
>##### I don't see why not.  It's based on sound principles.  It works.
>If we try to use a 'general' notion of context we will dissolve into smoke.
>##### You're being too pessimistic.
>And in any case, the purely functional requirements of distributed 
>knowledge-processing architecture require that we reduce such 
>contextuality as much as possible. Take your second example, where a 
>sentence's truth depends on the 'context' of the document in which it occurs,
>##### There are two parts to the statement from your document.
>##### 1. Names denote things in the universe.
>##### 2. Sets of triples denote truth-values.
>##### We both agree that 1. is true.  Statement 2. is true in your 
>document because you define the denotation of sets of triples to be 
>truth-values.  Statement 2. is false in my document because I define the 
>denotation of sets of triples to be things in the universe (facts of reality).
>and ask yourself what happens when parts of such documents are being 
>distributed across optical fiber, processed, inferences drawn from them, 
>conclusions archived and then re-transmitted arbitrarily long times later, 
>and used in other contexts far from their original source. If meaning 
>depends on contexts which can vanish in microseconds, as they will in the 
>SW, then meaning becomes meaningless.
>##### Meaning needs to be pinned down with good definitions.
>
>Pat
>
>>============
>>Dick McCullough
>><http://rhm.cdepot.net/>knowledge := man do identify od existent done
>>knowledge haspart proposition list
>>----- Original Message -----
>>
>>From: <mailto:phayes@ai.uwf.edu>pat hayes
>>
>>To: <mailto:rhm@cdepot.net>Richard H. McCullough
>>
>>Cc: <mailto:bwm@hplb.hpl.hp.com>Brian McBride ; 
>><mailto:www-rdf-comments@w3.org>www-rdf-comments@w3.org
>>
>>Sent: Tuesday, December 03, 2002 12:39 PM
>>
>>Subject: Re: context (comments on 
>><http://www.w3.org/TR/2002/WD-rdf-schema-20021112/>http://www.w3.org/TR/2002/WD-rdf-schema-20021112/)
>>
>>
>>
>>>Just two quick comments on context -- stimulated by your previous 
>>>comments on context.
>>
>>
>>
>>
>>1. Context is always important.
>>
>>
>>
>>I might take that comment seriously if I knew what it meant.
>>
>>
>>
>>>Here's a trivial example.
>>         Dick McCullough is married.
>>
>>In the context of December 2002, this statement is false.
>>
>>In the context of any time between June 1960 and September 1996, it's true.
>>
>>
>>
>>No. It was true AT one time but not AT another; or, it was true OF one 
>>time but not OF another; or, it is incompletely specified as stated and 
>>hence neither true not false, but rather something like a predicate which 
>>applies to temporally located entities.
>>
>>
>>
>>>
>>Here's another example.
>>
>>         Names denote things in the universe, and sets of triples denote 
>> truth-values.
>>
>>which is true in the context of your document 
>><http://www.w3.org/TR/2002/WD-rdf-mt-20021112/>http://www.w3.org/TR/2002/WD-rdf-mt-20021112/
>>
>>but is false in the context of my document 
>><http://rhm.cdepot.net/doc/KEtutorial.txt>http://rhm.cdepot.net/doc/KEtutorial.txt.
>>
>>
>>
>>Documents are not contexts in your first sense, and truth is not defined 
>>with respect to documents in any case.
>>
>>
>>
>>>
>>2. Knowledge is advanced by integrating facts into a wider context.
>>
>>For example, in physics,
>>
>>         force = mass x acceleration
>>
>>is a principle which integrates observed facts from many different 
>>contexts into a single context.
>>
>>
>>
>>
>>
>>Nonsense. Cite me any physics textbook which refers to such a notion of 
>>'context'.
>>
>>
>>
>>>By expanding that context to include variable mass and acceleration, we 
>>>get a broader principle
>>         force = rate of change of momentum
>>
>>
>>
>>Your message illustrates the central problem with the word 'context': it 
>>means everything, and so it means nothing. You use it above in three 
>>distinct senses which have got nothing whatever to do with one another, 
>>and it has been used to mean anything from a single token of a phrase in 
>>a particular utterance to an entire culture or human epoch. I have been 
>>to maybe six or seven workshops, colloquia, etc., on the topic of 
>>'context' and I don't think I have yet heard two people agree on a 
>>definition of the word. On one memorable occasion I listened to talks 
>>every hour for 3 working days, and kept careful records, and NONE of them 
>>agreed with ANY of the others.  My own considered opinion is that 
>>'context' is a kind of dustbin category, used by people to refer to that 
>>part of the problem of specifying meaning they don't yet understand properly.
>>
>>If you can come up with something like a definition of what you mean, I 
>>would be interested in discussing how to formalize it. Your first sense, 
>>which has to do with temporal distinctions, has already been thoroughly 
>>analyzed and formally specified.
>>
>>
>>
>>Pat
>>
>>
>>
>>>============
>>>Dick McCullough
>>><http://rhm.cdepot.net/>knowledge := man do identify od existent done
>>>knowledge haspart proposition list
>>
>>
>>
>>
>>--
>>
>>---------------------------------------------------------------------
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>>40 South Alcaniz St.                    (850)202 4416   office
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>
>
>
>--
>
>---------------------------------------------------------------------
>IHMC                                    (850)434 8903   home
>40 South Alcaniz St.                    (850)202 4416   office
>Pensacola                               (850)202 4440   fax
>FL 32501                                        (850)291 0667    cell
>phayes@ai.uwf.edu                 http://www.coginst.uwf.edu/~phayes
>s.pam@ai.uwf.edu   for spam
Received on Wednesday, 4 December 2002 12:44:36 GMT

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