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Re: Statements/Reified statements

From: Graham Klyne <GK@Dial.pipex.com>
Date: Thu, 23 Nov 2000 11:15:34 +0000
Message-Id: <4.3.2.7.2.20001123110718.00bd6510@pop.dial.pipex.com>
To: Jonas Liljegren <jonas@rit.se>
Cc: Sergey Melnik <melnik@db.stanford.edu>, ML RDF-interest <www-rdf-interest@w3c.org>
At 09:51 AM 11/23/00 +0100, Jonas Liljegren wrote:
>Graham Klyne <GK@Dial.pipex.com> writes:
>
> > I think it is necessary to distinguish between 'statings' and
> > 'quotings' of statements.  Reification is a way to do that within
> > the RDF model as currently defined.  Are there others?
>
>Every statement is stated in a specific context.  The stating is true
>within the context and othervise false.
>
>One common way to implement RDF is to have a fact boolean for every
>statement indicating if it's only a reified statement or the actual
>statement.

OK, that seems reasonable.  In particular, it seems a reasonable 
implementation of something that describes the same properties as 
reification per RDF M&S.

>But it would be better to indicate in which models/contexts the
>statement is true.

Well, yes, I happen to emphatically agree [1].

>This means that a quoting of a statement not considered to be true can
>be done by refereing to a statement belonging to another
>model/context.
>
>
>This means that instead of four, we have five:
>
>{ uri, pred, subj, obj, model }

I considered that approach for [1], but have preferred to use properties to 
create the association between statement-resource and context (model).  The 
above approach allows a given statement to be associated with only one 
context/model, where properties allow a given statement-resource to be 
incorporated into any number of contexts/models.  That seems very much more 
in line with the RDF philosophy of "anyone can say anything about anything".

#g
--

[1] (Work in progress) 
<http://public.research.mimesweeper.com/RDF/RDFContexts.html>

------------
Graham Klyne
(GK@ACM.ORG)
Received on Thursday, 23 November 2000 06:53:13 GMT

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