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

On Jan 9, 2006, at 3:55 AM, Enrico Franconi wrote:

> On 9 Jan 2006, at 03:37, Bijan Parsia wrote:
>
>> On Jan 8, 2006, at 6:10 PM, Enrico Franconi wrote:
>>
>>> 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).
>>
>> Yep. But are these people wanting to use OWL for anything? UML maybe, 
>> though I've not seen *UMLers* step up and request this stuff. You're 
>> experience might vary. If there were a clear UML application (ICOM? 
>> :)) that we were targeting as a kind of killer app for owl, I would 
>> find that example more compelling. But then I'd want a plan for 
>> sweeping the UML folks off their feet.
>
> Aggregation is ubiquitous in databases and SQL.

We aren't disagreeing.

> It is not present in standard conceptual modelling languages (e.g., 
> EntityRelationship E/R data model) for historical reasons (they came 
> before SQL). It has a minor presence in UML (the association with a 
> diamond at one end) - but UML was not conceived as a database 
> conceptual modelling language. There is *plenty* of proposals for 
> extension of the E/R data model (and for UML) to model conceptually 
> aggregations, and all the conceptual modelling tools I know about have 
> some (non-standard) hook to model aggregation.

With no clear winner. We're not talking overall utility or 
significance, but what has the right balance between utility, ease of 
marketing, and easy implementability. For *1.1*, treading where there 
is non-standardness elsewhere seems a little off target. Plus, there is 
no proposal on the table.

(This seems critical to OWL 2.0 as is a more elaborate form of 
metamodeling, but it doesn't seem to be a nigh trivial win.)

>  DL people (me, Uli, et al) did study extensions of DLs with 
> aggregations, and I came up with an extension of E/R (and UML) which 
> (a) is implemented in ICOM (the DL based conceptual modelling tool), 
> and (b) deserved a chapter in a Datawarehouse design book :-).

I think ICOM is a wonderful tool, but what I *don't* see is that it, or 
things like it, are widely used. My *personal* strategy would be to 
revive ICOM and try to build a user base for it (or get one of the 
vendors to sell it).

> I also mentioned aggregation since I'd say it is the typical use case 
> for meta-modelling.
> If OWL starts to catch up to model databases and more generally 
> information integration (which we really hope!), then aggregation will 
> become ubiquitous as well.

I agree.

>  I wonder whether people in the SWBP WG came up with such a modelling 
> requisite.

Good question.

>> Or more simply, I don't know what the dominant set of users for 
>> robust metamodeling are thus have a hard time assessing the utility 
>> of standardizing various proposals. Annotations (with full punning) 
>> are ubiquitous and highly desired and (mostly) easy. So I find them 
>> reasonable for 1.1.
>
> The reason why they are ubiquitous in OWL is because they are already 
> as a partial feature in OWL.

Let me totally concede that....let me *stipulate* that (though I've 
never said or thought otherwise). How is this a point against me in 
this dialectic? All I can see is that you could claim that aggregates 
would be equally ubiquitous if only they were present even if in a 
partial form. Let's stipulate *that*, that doesn't establish 1) that it 
will be easy to articulate and decide between proposals, 2) implement 
in all the major reasoners and editors (remember, we're hoping to have 
all of OWL 1.1 well
on the way to ubiquitously implemented by *May*!).

Cheers,
Bijan.

Received on Monday, 9 January 2006 13:13:09 UTC