Re: AW: Peter's slides about the MOF metamodel

In my view the situation should be handled in one of two ways:

Either:
1) The Model is presented in one place, and portion of a document  
that defines a syntax explicitly gives how one maps from the syntax  
to the model or
2) The Model that is presented interleaved with the functional style  
syntax models that syntax.

The current situation asks for confusion. We have two different  
things presented as if they are one.

-Alan


On Jul 30, 2008, at 8:34 PM, Peter Haase wrote:

>
> Hi Conrad,
>
> I agree with you that it is possible to come up with multiple  
> metamodels of
> the same language, but this is (in my view) not so much due to the  
> variety
> of syntaxes, but rather due to design choices one makes.
> The OMG made the design choice to provide a metamodel of OWL 1 that  
> models
> the OWL language as an extension of the RDF language (to be  
> precise: of the
> RDF data model, not a specific RDF syntax). A different approach  
> was taken
> in the metamodel for OWL DL we developed in our group [1], which  
> rather
> provides a Description Logic oriented view, independent of RDF  
> (closer to
> the model of the abstract syntax).
>
> In any case, the metamodel for OWL 2 is intended to provide the  
> structural
> specification of the OWL 2 language independent of a specific  
> serialization
> syntax. There may be many concrete syntaxes. For some syntaxes the  
> mapping
> will be trivial (XML Schema), for others more complex (RDF).
>
> Regards,
> Peter
>
> [1]
> http://www.aifb.uni-karlsruhe.de/WBS/sbr/publications/ontology- 
> metamodeling.
> pdf
>
>
>
> -----Ursprüngliche Nachricht-----
> Von: public-owl-wg-request@w3.org im Auftrag von Conrad Bock
> Gesendet: Mi 30.07.2008 15:25
> An: 'Boris Motik'; public-owl-wg@w3.org
> Betreff: RE: Peter's slides about the MOF metamodel
>
>
> Peter, et al,
>
> You might have discussed this already regarding metamodel  
> alignment, but
> languages with multiple concrete syntaxes like OWL might have multiple
> metamodels.  This is because metamodels often just remove concrete
> notational elements like punctuation and graphical shapes, and add
> relations that are expressed with juxtapostion in the concrete syntax.
> The OMG's OWL 1 metamodel is based on the RDF/XML syntax, the OWL 2
> metamodel is based on the "W3C abstract" syntax (which is concrete in
> OMG terms).
>
> Since the RDF/XML and "W3C abstact" syntaxes are so different,  
> there are
> potentially two metamodels for each version of OWL.  A couple  
> options to
> reduce this to one metamodel per version might be:
>
>   - mapping one metamodel to multiple concrete syntaxes.  These  
> will be
>     complicated for metamodels and concrete syntaxes that don't
>     correspond to each other.  For example, mapping the OWL 1  
> metamodel
>     to the OWL RDF/XML syntax would be more straightforward than to  
> the
>     OWL 1 W3C abstract syntax.
>
>   - Choose one concrete syntax per version for the metamodel,  
> preferably
>     the same kind in each version. Since the OMG OWL 1 metamodel used
>     the RDF/XML syntax, it would be easiest for migration if the OWL 2
>     metamodel is derived from the RDF/XML syntax, rather than the
>     W3C abstract syntax.
>
> All the options I'm aware of have problems, just wanted to give my  
> take
> on the tradeoffs.
>
> Conrad
>
>
>
>

Received on Tuesday, 5 August 2008 07:42:46 UTC