Re: modelling issue?

Thanks Dan and Lin

>
> Domain and range are characteristics of properties (aka
> relationships, attributes), rather than of the things those properties
> relate to. And yes, they're not mandatory, you can declare and use a
> property without saying anything
> about it's domain or range.
>


Okay, in another, offlist reply, among other comments I receve the following
statement

Most books I have read state that you should be cautious about making domain
> and range statements about properties.  The results, the books claim, are
> difficult to predict in large ontologies.
>

I seem to get two contradictory statements there (and it would not be the
first time, argh - I get different people telling me different things about
this), and not sure how to interpret them in relation to each other
sorry if it's me actually missing out something


>
>  RDF expresses everything in terms of triples. Sometimes the triple is
> a relationship between a thing and another thing (which is often but
> not always named with a URI). And sometimes the triple is a
> relationship between a thing and a string (possibly language-tagged or
> data-typed). RDF actually calls the link in both cases a "property",
> but sometimes for communicating in other contexts you'll here
> "relation" or "relationship" (typically when the link isn't to a
> literal string value). And sometimes you will hear "attribute",
> usually when the value is a string literal.
>

okay, in the modelling world,  that would be regarded as something to be
worried about,
we call these 'conflicts'
when one thing can be interpreted in more than one way, the system is likely
to be brittle



> We had an army of logicians and mathematicians go over the 2004 specs
> in great detail. They may have missed something, but I suspect our
> main difficulties are elsewhere...
>

well, maybe  a systems engineering perspective would provide additional
views, or a system of systems engineering (as in network of networks),




> > Are the above points addressed in some RDF tutorial
>
> Did you see http://www.w3.org/TR/rdf-primer/ ?
>
> yes s its a great reference document, but it s very long to read it word by
word, and there is no indication that it contains
the answers I am looking for

Lin,
Jim H book is something that I want to get my hands on too, surely, still
questions may have to be answered to issues
that are not directly or explicitly addressed in the literature, I havent
been able to set aside time to read it, but I ll try to accsss those chaps
straight away

P