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Re: Impact of monotonicity in RDF (was: Social Meaning and RDF)

From: Graham Klyne <GK@NineByNine.org>
Date: Thu, 06 Feb 2003 21:00:28 +0000
Message-Id: <5.1.0.14.2.20030206205219.00a120c0@127.0.0.1>
To: Seth Russell <seth@robustai.net>
Cc: pat hayes <phayes@ai.uwf.edu>, RDF interest group <www-rdf-interest@w3.org>

[I drafted this before I read Pat's response, but am sending it anyway 
because I think we're saying different, but entirely compatible, things.]

At 10:27 AM 2/6/03 -0800, Seth Russell wrote:
>Im sorry but I cannot grok this reasoning.
>
>Granted, we cannot assume we have all the facts.  Granted, the truth of 
>our conclusions are always dependant upon the truth and *completness* of 
>our premises.  How can monotonicity change that predicament in the 
>slightest?  I keep hearing:  "We know that we cannot conclude 
>such-and-such because we might be missing some information, so we *must* 
>change all the vocabulary and inference patterns to  be monotonic,  and 
>then  we *can* draw such a conclusion.   Huh, what changed - what suddenly 
>made drawing unwarrented conclusions valid?   How can we suddely make 
>statements that are always true?

I'm not sure I know how to answer this adequately.

There's no question here that unwarranted conclusions somehow become valid.

I guess that, as people, we are used to dealing with the lingering 
uncertainties of non-monotonicity.  But simple formal reasoning systems 
don't have the mechanisms to do this.   I'm no expert, but I expect there 
have been attempts to develop systems with non-mon capabilites, and I'd not 
be surprised if they become pretty difficult to manage.  So, for practical 
implementation, it's easier to use monotonic systems for automated 
reasoning.  This in turn means that input information is presented in a 
form compatible with the logic used.

The point I was trying to make in my original posting is that this means 
you sometimes have to think carefully about the form of the raw facts you 
are able to use.

#g


-------------------
Graham Klyne
<GK@NineByNine.org>
Received on Friday, 7 February 2003 10:01:41 GMT

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