W3C home > Mailing lists > Public > public-owl-wg@w3.org > November 2007

Re: proposal - Fragments redux (unifying the threads under Issues 75-80)

From: Carsten Lutz <clu@tcs.inf.tu-dresden.de>
Date: Thu, 29 Nov 2007 08:44:41 +0100 (CET)
To: Jim Hendler <hendler@cs.rpi.edu>
Cc: Bernardo Cuenca Grau <bcg@cs.man.ac.uk>, OWL Working Group WG <public-owl-wg@w3.org>
Message-id: <Pine.LNX.4.64.0711290836030.28024@frege.inf.tu-dresden.de>

On Wed, 28 Nov 2007, Jim Hendler wrote:
>
> well, it's not so much motivated by computational properties, see out in the 
> real world there's people who just implement fast engines and don't worry so 
> much about the details...

Sorry to object, but IHMO this approach is precisely why the original
OWL Lite was broken. And I understood we wanted to fix this?! We should
at least understand the computational properties of the fragments we
are selecting.

> but, what is the motivator is that several studies of ontologies including 
> the one we did at Maryland a couple years back [1], a recent study by Guus 
> and Frank van Harmelen (I don't have a reference, was told about it by Guus 
> and Frank), and a study by UMBC of Swoogle results (blogged in eBiquity last 
> year) all showed that most of the currently most used ontologies (including 
> FOAF) pretty much fall into this class.  I've also met with several companies 
> involved in OWL startups, and this is the expressivity that most of them say 
> is most useful.

Good to know. On the other hand, they could just use OWL full if it
turns out that that particular fragment is neither computationally
easier nor more efficiently implementable than the whole OWL-DL. I'd
like to support Bernardo when he says that years of research have been
invested into the other fragments, they are very well-understood, and
were very carefully build. We should definitely take advantage of
that. Regarding usefulness: EL++ *is* used by loads of real-world
ontologies, and that was the case even before EL++ was "discovered" by
the DL research community. No studies needed. :)

Never mind, I couldn't resist to point these out now. Maybe this is
best discussed at the Manchester F2F.

greetings,
 		Carsten

--
*      Carsten Lutz, Institut f"ur Theoretische Informatik, TU Dresden       *
*     Office phone:++49 351 46339171   mailto:lutz@tcs.inf.tu-dresden.de     *
Received on Thursday, 29 November 2007 07:44:58 GMT

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