RE: What do the ontologists want

>
>I observe real disconnect on the list between reification in RDF and
>reification as understood in logic and KR circles, very like the RDF
>use of the term Model, as was beaten to death last year and caused
>some hostility.

The reference documents for RDF introduce 'reification' by making 
explicit reference to the use of this (highly technical) word in KR, 
and provide no other explanation apart from illustrative examples 
which seem to suggest the same meaning.  So I fail to see how there 
can be a disconnect, unless the RDF community has somehow managed to 
invent a new meaning all by itself. This is meant perfectly 
seriously: often, new senses of technical terms do emerge by a kind 
of working consensus. But I wish someone - SOMEONE - would make an 
effort to say clearly what the sense of 'reification' used in RDF 
actually is. I havnt been able to find a coherent meaning yet other 
than the KR one.

>I'd like to put up a straw man hack for mentioning in RDF.
>Then I'd like to consider the implications of moving between use and
>mention, when M&S reification only is used as someone who's had a crack
>at implementing query for RDF stores and whose conclusion is that handling
>RDF reification is at least difficult.
>
>I think that these two are not at all the same:
>
>1: RDF reification is a technique to make statements about
>statements.
>
>2: KR reification is a technique for objectifying a statement.

These seem to me to be clearly identical. Maybe you mean something 
more by 'objectifying' than I do, but calling something an 'object' 
(or an 'entity') in KR simply means that it is considered to be in 
the semantic domain of description, and this is exactly what is 
implied by saying that one is making statements about it. Objects 
*are* things that one makes statements about (actually, it would be 
better to say, things that one could make statements about, but thats 
a technical quibble.).

Maybe you could elaborate on what you see as the distinction here?

Pat Hayes

PS
>
>There's nothing wrong with flyweight pattern matching or inference for
>RDF so long as the engine builders and users know the limitations of
>what they can sensibly ask of such a system.

I'll agree with that, but add that one needs to be ready for the 
flyweight to sometimes drop the ball.

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Received on Wednesday, 16 May 2001 17:45:01 UTC