[XML-SIG] XMI question

[Thomas B. Passin]

<uche.ogbuji@fourthought.com> wrote
<snip/>

> I would quite disagree.  First of all, I think that for most purposes,
UxF, a
> David against the XMI Goliath, is a better (certainly simpler)
serialization
> of the UML meta-model for several purposes.  But even if you are merely
> advocating UML, I would claim that even though I'm an experienced OO
developer
> and a strong advocate of OO over other methodologies for _application_
design,
> I think it is woefully inadequate for generalized data modeling.
>
Yes, there's more to data modeling than schemas, even OO schemas.

> True, some of its shortcomings help present brain explosion (for instance,
> even RDF avoids N-ary relationships) but it often imposes unnatural
> constraints on data, such as those encoded in traditional OO sub-typing.
The
> solution is to go one step lower.  OO builds a model specialized for app
> development on top of such more fundamental models as conceptual graphs
and
> RDF.  For general data modeling, I suggest these latter models, since they
are
> more general and powerful than the OO sub-set.
>
Nice to hear that someone else looks favorably on conceptual graphs.  I
assume you mean Sowa's conceptual graphs?  For developing data models, I
find I like to use an informal hybrid between high-level OML (Open Modeling
Language - something like UML but cleaner and more adaptable) and conceptual
graphs.  Once the real shape of the model becomes clear, you can decide if
you want to realize it as a relational database, an object database, or
whatever.

Conceptual graphs can be expressed in KIF (Knowledge Interchange Format) or
in their own serialization format.  On the other hand, UML, OML, and
conceptual graphs are all implemented graphically as boxes (nodes), lines
(arcs), and annotations.  So it would seem that any language that can
represent arbitrary collections of node and arcs should be able to represent
CGs, KIF, etc. I've been speculating whether KIF can be represented in
XML -haven't done anything but speculate so far, though.  Sowa showed how to
extend CGs to 2nd order logic, which is enough to allow them to represent
schemas.  So there might be another route to marry schemas and XML, via CGs
and/or KIF.

Regards,

Tom Passin