Re: why are properties decoupled from classes

On 10/26/05, Frank Manola <fmanola@acm.org> wrote:

> >>>This seems to work quite well for the age (in years) of persons.
> >>>However, this does not work for, for example, the age of particles in a
> >>>particle accelerator.
> >>>
>
> This is a good point.  There certainly may be subtle (or not-so-subtle!)
> distinctions between the semantics of a general concept like "age" as
> applied to different kinds of things. However, remember that in RDFS
> you're not really defining *the* "age" property, but a *particular*
> "age" property, identified by a URI.  Best practices for modeling is a
> subject for separate (and lengthy!) discussion, but I could certainly
> see some possible justification for a model having, rather than one
> property with different class-based constraints, two different
> properties (say foo:age and bar:age, perhaps as subproperties of a more
> general one) for this example.  In that case, different range
> constraints on the two properties might be appropriate.  However, YMMV.
> In any event, I think we agree that we want to be able to say exactly
> what we mean, without the language somehow forcing us to say more or
> less than that!

A little tangential question, do you think this suggests that the
"OntoWorker" kind of approach makes more sense, disposing of
scruffiness like literals and (XSD-styled) datatypes...or does the
pragmatic value of those things clearly outweigh having a more easily
manageable formal model?

Cheers,
Danny.



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