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Re: REQDOC: closed worlds

From: Deborah McGuinness <dlm@KSL.Stanford.EDU>
Date: Mon, 25 Feb 2002 19:29:39 -0800
Message-ID: <3C7B0123.23097E5A@ksl.stanford.edu>
To: Frank van Harmelen <Frank.van.Harmelen@cs.vu.nl>
CC: WebOnt <www-webont-wg@w3.org>
one minor suggestion follows.
this is motivated by my experiences in configuration where it was important to be
able to make closed world statements.

frank suggested:
Therefore, the language must be able to state that a given ontolog can be
regarded as complete. This would then sanction additional inferences to be
drawn from that ontology. The precise semantics of such a statement (and the
corresponding set of inferences) remains to be defined, but examples might
include assuming completeness of class-membership and assuming exhaustiveness
of subclasses.

i suggest the minor modification:

Therefore, the language must be able to state that a given ontolog can be
regarded as complete. This would then sanction additional inferences to be
drawn from that ontology. The precise semantics of such a statement (and the
corresponding set of inferences) remains to be defined, but examples might
include assuming complete property information about individuals, assuming
completeness of class-membership, and assuming exhaustiveness
of subclasses.
Frank van Harmelen wrote:

> Current wording:
>
> Due to the size and rate of change on the Web, the closed-world assumption
> (which states that anything that cannot not be inferred is assumed to be
> false) is inappropriate. However, there are many situations where closed-world
> information would be useful. Therefore, the language must be able to specify
> when certain documents have complete information on certain topics. Examples
> might include the complete set of instances of a class or the complete set of
> members in a list.
>
> Proposed Wording:
>
> ... two sentenced remain unchanged ...
> Therefore, the language must be able to state that a given ontolog can be
> regarded as complete. This would then sanction additional inferences to be
> drawn from that ontology. The precise semantics of such a statement (and the
> corresponding set of inferences) remains to be defined, but examples might
> include assuming completeness of class-membership and assuming exhaustiveness
> of subclasses.
>
> Comments:
> 1. I refer to Pat's email [1] for keeping this on board
> 2. I tried to make the issue clear while keeping the details open as much as
> possible (there is clearly work to be done here).
>
> Frank.
>     ----
>
> [1] http://lists.w3.org/Archives/Public/www-webont-wg/2002Feb/0098.html

--
 Deborah L. McGuinness
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Received on Monday, 25 February 2002 22:34:17 GMT

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