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Re: a simple question

From: Dan Connolly <connolly@w3.org>
Date: Fri, 05 Dec 2003 15:35:21 -0600
To: Drew McDermott <drew.mcdermott@yale.edu>
Cc: www-rdf-rules@w3.org
Message-Id: <1070660121.13847.108.camel@dirk.dm93.org>

Responding in part, using text that's already written...

On Fri, 2003-12-05 at 12:38, Drew McDermott wrote:
>    [Dan Connolly]
>    I suggest that checkable valid conclusions are
>    essential to anarchic scalability.
> A fond wish, but one that can't be granted.
> Suppose a web service offers a warehouse-truck scheduling algorithm.
> The algorithm is widely used and endorsed by several major truckers,
> but it comes with no optimality guarantee.  Your agent uses the output
> of the algorithm as one step in an inference concerning a
> preventive-maintenance schedule for your trucks for next month.
> In what sense are the outputs of the algorithm checkable _or_ valid?

"Parties that don't use logic to justify their data can use digital
signatures, and LogicalReflection techniques integrate signatures into
the proof system so that trust policies can be manipulated in-band with
the rest of the data.  For example... "

 -- http://esw.w3.org/topic/SemanticWebBus

> I fear that this is the usual case, not an outlier.  That's why
> "undisciplined" use of negation-as-failure doesn't scare me.  It's
> just allowing useful heuristicism to appear in small doses amidst
> logical inferences, on the grounds that the logical inferences will
> mainly be glue between large-scale computations permeated with
> heuristicism.

Yes and no; more when I find time, I hope...

> Maybe this is a good way to think about it: Many inferences are
> justified by statements of the form, "Here's my conclusion and my
> grounds for believing it; just try to refute it."  That is, checking
> is not just a matter of verifying that each step is actually justified
> by an inference rule.  It can also be a matter of trying to find a
> better conclusion than the one offered.
>    I wish I could elaborate, but I'm juggling too many
>    things just now. I hope you don't mind my using
>    your inboxes to bookmark my thought.
>    The relevant wiki nodes are these, though I don't
>    think they make my point quite yet either:
>      http://esw.w3.org/topic/AnarchicScalability
>      http://esw.w3.org/topic/SemanticWebBus
> I will take a look.

I look forward to discussing it further.

>                                              -- Drew
Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Friday, 5 December 2003 16:35:22 UTC

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