Re: Publications about OWL (1 or 2) Full

First, thanks to you Michael and Markus for your replies.

Now, Michael,

Le 19/05/2011 19:42, Michael F Uschold a écrit :
> Thanks for a thorough reply.  See comments inline.
>
> On Thu, May 19, 2011 at 3:09 AM, Markus Krötzsch<
> markus.kroetzsch@comlab.ox.ac.uk>  wrote:
>
>> 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).
>>
>
> Hmm, I know there is some limited punning, but these are two different
> things, not one thing appearing in two different places. The inference is
> very limited.

What Markus says here I guess is that, in spite of the limitations of 
the punning mechanism, a full-fledged OWL 2 DL reasoners will likely 
infer more things than *currently existing* incomplete OWL Full reasoners.

>
> I don't think there is a way to nicely handle the species example where
> Species is a class with instance Eagle with instances being individual
> eagles.

No problem:

:Species a owl:Class .
:Eagle a :Species, a owl:Class ;
   rdfs:subClassOf :Animal .
:billy a :Eagle .

This is valid OWL 2 DL.

Then, with a SPARQL 1.1 query with OWL 2 DL entailment regime, I can get 
the pairs <species,individualmemberofthespecies>:

SELECT ?species, ?member WHERE {
  ?species a :Species .
  ?member a ?species .
}

>
> I also do not think there is a robust solution to the classes as values
> problem.

What do you mean by "classes as values problem"?


>> 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.
>>
>>
> Thanks, I just had a look. It is intersting, and geared more for the
> theorist than the practitioner.  Do you know of a more practice-focused
> paper that gives examples of what you can and cannot do with OWL2
> metamodelling, compared to OWL-Full?
>
>
>> 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'm not sure what you mean by "make meaning clear" as a good DL compromise.
>   The example from that paper is the need to represent Eagle as an instance
> of Species so you can e.g. say it is on the engangered list.  DL forces you
> to represent Eagle as an as an individual that can not ever have any
> instances. But this is patently untrue -- to that extent, it obfusticates
> meaning.  If OWL2 metamodellign lets me do this, I'll be surprised and
> delighted.

Punning means that you can use the URI of an individual in place of the 
URI of a class. Therefore, :Eagle, as a class, can have instances (like 
:billy above) and as an individual it can belong to a class (like 
:Species). However, :Eagle-the-individual is different from 
:Eagle-the-class, although they share the same identifier.


Regards,
AZ.


>>
>> 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/
>>
>
>
>


-- 
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 - Fax: +33(0)4 72 43 87 13
Lecturer at:
Institut National des Sciences Appliquées de Lyon
20 Avenue Albert Einstein
69621 Villeurbanne Cedex
France
antoine.zimmermann@insa-lyon.fr
http://zimmer.aprilfoolsreview.com/

Received on Thursday, 19 May 2011 17:59:30 UTC