Re: Publications about OWL (1 or 2) Full

On 18/05/11 19:49, Michael F Uschold wrote:
> These are good questions. You are right, the current attitude and
> practice is avoid OWL Full at all costs.  Unfortunately, this ignores
> the costs of NOT using OWL Full -- basically it means having to do a lot
> of painful workarounds that make the ontology harder to understand which
> undermines one of the key goals of ontology: to make meaning clear!
>
> If you want to be able to have meta classes, and use classes as values
> for properties and other OWL Full goodies, you have to use a more
> powerful reasoner. Any FOL prover would do, I should think, but I am no
> expert.

Fortunately, OWL 2 now allows a useful form of simple meta-modelling 
now, so that you can indeed have meta classes and use classes as 
subjects and objects of properties. The logical inferences that OWL 2 DL 
tools draw from this are limited, but may still be more than what any 
particular OWL 2 Full reasoner would give you (depends on the OWL 2 Full 
reasoner you have -- I am not aware of much implementation work there 
beyond OWL 2 RL).

An insightful discussion of meta modelling semantics -- the one of OWL 2 
DL (punning) and a stronger one -- is found in the paper:

Boris Motik. On the Properties of Metamodeling in OWL. Journal of Logic 
and Computation, 17(4):617–637, 2007.

A big advantage of OWL 2 DL in this respect is that it makes it legal to 
state such meta-knowledge without violating any constraints of the 
language. The OWL Full semantics may still formally lead to more 
consequences, but in practice what matters is how many of the total 
consequence any tool will actually give. So the DL approach could be a 
good compromise (especially to "make meaning clear" beyond purely 
logical/formal aspects).

I think the more important case where ontologies go beyond OWL DL is due 
to the structural constraints related to transitivity and property 
chains (e.g. it is easy to get forbidden cycles in property chain 
dependencies). But the interesting difference to the earlier 
meta-modelling limitations of OWL 1 DL is that in these cases, the 
semantics of OWL DL is in principle still meaningful and well-defined in 
its common first-order logic framework. It is simply known that 
computing consequences of this semantics becomes undecidable, and thus 
the decidability-loving DL tools reject the inputs right away.

But again anybody who would venture to implement OWL Full reasoning 
could also look into "OWL DL reasoning for ontologies violating the 
structural restrictions." This task might be easier to solve in practice 
since one could probably reuse existing algorithms and tools to solve 
part of the problem. It is also part of ongoing research to weaken the 
structural restrictions further, so one already knows of complete 
algorithms that could achieve this in some cases that OWL DL excludes.

Also note that "FULL" and "DL" now refer to syntactic languages only. 
The semantic distinction is now made between "direct semantics" and 
"RDF-based semantics". This helps a bit to avoid confusion between 
syntax and semantics. So my last remark was about finding ways to 
evaluate (more of) OWL 2 FULL under direct semantics.

Cheers,

Markus

>
> I have no hard evidence, but I feel certain that there are plenty of
> cases when the penalties of OWL Full are on balance small enough
> compared to the gains of expressive convenience and clarity of OWL Full.
>
> I would love to see someone look into this. I would love it if someone
> tried to create a reasoner that handled OWL Full as efficiently as possible.
>
> Notice how many responses you got to this message in the past few weeks?
> That may reflect how much people in the community care about OWL Full!
>
> Michael
>
> Michael
>
> On Sat, Apr 23, 2011 at 1:05 AM, Antoine Zimmermann
> <antoine.zimmermann@insa-lyon.fr
> <mailto:antoine.zimmermann@insa-lyon.fr>> wrote:
>
>     Dear all,
>
>
>     I'm looking for scientific publications related to OWL Full. I'm
>     interested in the following kind of work:
>       - reasoning with OWL Full;
>       - modelling ontologies in OWL Full;
>       - properties of OWL Full, or relationships between OWL Full and
>     other formalisms.
>
>     I've found some papers about modelling existing ontologies in OWL
>     (for instance, modelling a UML spec or a frame-based ontology in
>     OWL) which happen to fall into OWL Full, but nothing about modelling
>     OWL Full ontologies by design. I found very little about reasoning
>     in OWL Full (with the notable exception of [1], which also relates
>     OWL reasoning to OOP).
>     But the vast majority of papers mentioning OWL Full present it as
>     the language that must be avoided at all cost (usually saying "if we
>     do that, we are in OWL Full" implying "if we do that, we're screwed!").
>
>     Thanks in advance for your pointers.
>
>
>     [1] Seiji Koide and Hideaki Takeda. OWL-Full Reasoning from an
>     Object Oriented Perspective. In R. Mizoguchi, Z. Shi, and F.
>     Giunchiglia (Eds.): ASWC 2006, LNCS 4185, pp. 263–277, 2006.
>     Springer-Verlag Berlin Heidelberg 2006.
>
>
>     Regards,
>     --
>     Antoine Zimmermann
>     Researcher at:
>     Laboratoire d'InfoRmatique en Image et Systèmes d'information
>     Database Group
>     7 Avenue Jean Capelle
>     69621 Villeurbanne Cedex
>     France
>     Tel: +33(0)4 72 43 61 74 <tel:%2B33%280%294%2072%2043%2061%2074> -
>     Fax: +33(0)4 72 43 87 13 <tel:%2B33%280%294%2072%2043%2087%2013>
>     Lecturer at:
>     Institut National des Sciences Appliquées de Lyon
>     20 Avenue Albert Einstein
>     69621 Villeurbanne Cedex
>     France
>     antoine.zimmermann@insa-lyon.fr <mailto:antoine.zimmermann@insa-lyon.fr>
>     http://zimmer.aprilfoolsreview.com/
>
>
>
>
> --
> Michael Uschold, PhD
>     Senior Ontology Consultant, Semantic Arts
>     LinkedIn: http://tr.im/limfu
>     Skype, Twitter: UscholdM
>


-- 
Dr. Markus Krötzsch
Oxford  University  Computing  Laboratory
Room 306, Parks Road, Oxford, OX1 3QD, UK
+44 (0)1865 283529    http://korrekt.org/

Received on Thursday, 19 May 2011 10:09:49 UTC