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RE: [OEP] "Classes as values" first draft

From: NANNI Marco FTRD/DMI/SOP <marco.nanni@francetelecom.com>
Date: Thu, 15 Apr 2004 18:49:47 +0200
Message-ID: <BBBE5BAA3B351C488C415EA662EA88400B712D@ftrdmel2.rd.francetelecom.fr>
To: "Jim Hendler" <hendler@cs.umd.edu>, <public-swbp-wg@w3.org>
I quite agree with you.
What i wanted to express with my comment was  that when i see "the
ontology is in OWL FULL", according to what i can read in the OWL guide
"OWL Full is meant for users who want maximum expressiveness and the
syntactic freedom of RDF with no computational guarantees. " people can
think that it's, at first or at least,  not a good thing to be in OWL
I think of course that it is neither a bad thing nor a good one but i
also think that people can't refrain from thinking that.
What does "no computational guarantees"  mean for a relative new comer
in the SW world ?
DL world and reasoning problems are not easy things. And i think, i'm
convinced, that  it's (or it could be) easier for people to choose the
first Natacha, approach because it's more straightfroward and clean and
by consequence to understand metamodeling than to :
        - generalize the other approachs in other use case,
        - and to understand DL and reasonning problems in general way
without concrete help or examples
What does "it is unlikely that any reasoning software will be able to
support every feature of OWL " exactly mean ? . Does it mean that i will
have core dumped when i will try to validate my ontology ? an infinite
loop ? a reject message like : " unable to validate you ontology because
..." or some error/warning message ? in this last case if i decide to
use my ontology in spite of these messages what kinds of problem will i
have at running time according to my use case ?
To be more precise : suppose that in the image use case of Natacha my
job is only to receive images and to classify them, if all the images
are annotated in such a way '(a good way) that i will never need to ask
the reasonner to classify them because the name of the class explicitly
appears in the annotation i don't care if i'm in OWL FULL. In this case
i'm lucky. 
But, generally ideal world don't exist, and i will probably meet some
page for wich the fact to be in OWL FULL will have 
perhaps heavy consequences for the integrity of my "running"
(Note : behind this problem there is an other important and complicated
question : do, ontology creators, have to build Ontologies very closed
to their uses case or to a particular use of the ontology OR do they
have to anticipate the maximum numbers of particulars uses ? In this
last case i think that they'll always be obliged to consider very
seriously the problem of having OWL Full ontologies or not)
That's why I think that it could be fruitful, if we are able to do that,
to give a list of the most current "possible" problems people can
encounter with OWL FULL Ontologies. 
If you think it's useful, i think that it could be great to have two
distinct things : 
       1) - for each point (e.g "classes as values as Natacha described)
and for each solutions we could add  to the Deborah proposal (for

> my summarization of these is:

> problem description   (including background   and observations could
fit in here as well)
> use case example
> abstracted solution
> owl solution
> implications
> references

> if as in natasha's example, there are many solutions, then repeat
abstracted solution, owl solution, implications, references > as

            concrete examples of what  OWL FULL implies when a solution
put the ontology in the OWL Full world
       2) - a more general chapter titled for example : "OWL Full : what
does it imply ?" which could contains even the same examples of the
listed points above
I think it will be very helpful for readers to have these two different
ways or two distinct entry points for these problems in the same
document. This could be fruitfully completed with a good index where we
could find entries like
                OWL Full 
                    - computing problems see :
                                    - patterns descriptions : page xx,
                                    - chapter "OWL Full : what does it
imply" : page zz
 To start the work i could propose to try to take the Natacha uses case
as a starting point and to show two different "instances" of it : one
for wich to be OWL FULL is not a problem an the other for which you can
have some problems.
Thank you very much
best regards 

-----Message d'origine-----
De : public-swbp-wg-request@w3.org
[mailto:public-swbp-wg-request@w3.org]De la part de Jim Hendler
Envoye : jeudi 15 avril 2004 16:24
A : NANNI Marco FTRD/DMI/SOP; public-swbp-wg@w3.org
Objet : RE: [OEP] "Classes as values" first draft

At 12:52 +0200 4/15/04, NANNI Marco FTRD/DMI/SOP wrote:

Perhaps that the fact to describe a blocking situation in the context of
this use case due to the fact that we are in OWL FULL, could help people
to better realize what to be in OWL FULL really means. My request comes
from the fact that when i tried to find such a situation/example it was
more difficult than i thought at first

Sure, as long as for any "blocking condition" that someone claims is
caused by being in OWL Full, we also include blocking conditions which
result from being in OWL DL/Lite (there are many that I'm encoutering in
my work these days) and also that we explore some new paradigms that are
yet relatively sparse -- for example, Mike Dean had some nice examples
(I think it was at a DAML meeting) of the idea of, essentially, taking
the OWL DL subset of an OWL Full document and it using it for some
reasoning (classification) tasks.
  Again, what I ask is that we remember we're in largely unexplored
space and we need to be very careful of being judgmental -- I have met
many people who believe in the future OWL DL will cease to exist and
everyone will just use something called OWL, I have met many people who
believe in the future OWL Full will cease to exist and everyone will
just use something called OWL, and I've met many people who think it
will continue as current - with perhaps more OWL profiles growing over
time (for example, the Gene Ontology folks have been thinking about how
to interact w/OWL, given they consider part-whole to be the most
important kind of representation for the applications they run) -- in
short, predicting the future is always difficult and we should be
careful to embrace multiple views
Professor James Hendler
Director, Semantic Web and Agent Technologies       301-405-2696
Maryland Information and Network Dynamics Lab.      301-405-6707 (Fax)
Univ of Maryland, College Park, MD 20742      240-277-3388 (Cell)
Received on Thursday, 15 April 2004 12:52:43 UTC

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