Re: [OWL] annotations and meta-modelling in OWL 1.1

On 8 Jan 2006, at 21:54, Bijan Parsia wrote:
> From various conversation with people who use OWL Full, and some  
> introspection, I see two primary, if only current, uses of higher  
> order like constructs (be they annotations, punning, or some more  
> full blown species of metamodeling): Metadata about the "symbolic  
> artefact", e.g., who wrote these axioms, when, when last modified,  
> etc. and for ontology alignment (e.g., I modeled Wines as a class  
> and you as an instance). I am not saying that these are the *only*  
> uses of higher order like constructs, but they are *in my  
> experience* what get mentioned. Only the latter has potentially  
> interesting modeling impact, and, in practice, people are just  
> happy to be able to *mark* these alignments and let some other  
> piece of software (usually not a reasoner!) take care of, e.g.,  
> conversions of data between ontologies.

Mmmhh, you are missing the *real* usages in the two biggest  
communities in informations system. In conceptual modelling, people  
do use metamodelling to characterise their object languages (I really  
don't like this, but this is a fact): see UML! In database systems,  
pleople use aggregation functions to characterise the values of  
properties of sets of tuples: see SQL! That is, you can have a  
property of a set of tuples defined in some way (e.g., average of the  
values of a property of all elements of the set of all tuples having  
some other property, etc).

--e.