RE: philosophy of SWBPD (was Re: [OPEN] and/or [PORT] : a practical question)

Jim Hendler says:
I guess it would be possible for using OWL separately from the Web, but
that is sort of like talking about using HTML separate from the Web --
why would you want to?   Seems a pretty borderline case.
Here is your borderline case, and may help to explain the context of my
earlier remarks. We wrote a paper that got accepted last year's ISWC
conference that used DAML+OIL. The application had little if anything
specifically to do with the Web, we just used DAML+OIL because it was an
emerging standard ontology representation language, and we had a
classification problem that was amenable to DL reasoning. DAML+OIL, of
course evolved from OIL, which also had nothing specifically to do with
the Web.  
I was hesitant to submit the paper on the basis of this dubious
relevance. It smacked too much of "if your program is in lisp or prolog,
then you must be doing AI". My co-authors over-ruled my concerns and I
was proved wrong. The paper got accepted and I gave the talk to a room
that was 80-100% full of people.  The predominant situation does indeed
seem to be that it if you use DAML+OIL (or OWL) then it must be relevant
to the Semantic Web (or at least, be of interest to the Semantic Web
Work on this project continues, and if we ever make it a Web
application, that will be independent from our choice to use
DAML+OIL/OWL.  So, I guess we are not using any of the webby portions of
OWL, and to date have not seen a need to (as far as I understand the
webby vs. non-webby portions of OWL).
-----Original Message-----
[]On Behalf Of Jim Hendler
Sent: Thursday, April 01, 2004 5:24 AM
Subject: RE: philosophy of SWBPD (was Re: [OPEN] and/or [PORT] : a
practical question)
At 10:28 +0200 4/1/04, NANNI Marco FTRD/DMI/SOP wrote:
Jim Hendler wrotes
>In case anyone hasn't figured it out by now - I THINK IT SHOULD BE
>Working Group.  If you'd like me to state it clearer, let me know
> what to addd
Do i understand well what you want to say :
        You think that, according to the formal definition of the term
"Ontology", building an ontology doesn't automatically mean that you are
in the SW context ?
I think that also according to many informal definitions of ontology --
the Semantic Web is one particular place for ontologies
        If it is what you mean i completely agree with that because  i
think that , like Mr LAPALICE, we have been building Ontology since, as
you say, 50 years without knowing it
well, we've been calling them ontologies (Ala Gruber) since the mid 80s,
although I first learned that term in my intro AI course in 1975 -- and
I suspect others on this group go back further.  Using a DL-like
approach to ontologies probably dates back to KL-ONE by Brachman in the
late 70s.
But you also write :
> They ARE central to the design of OWL, in the sense that OWL is
> specifically FOR the Web, and thus had to have a few things that
> typical KR/O languages lack.
Do I have to understand that what i have written above is false if I use
OWL (RDFS ?)? In other word if i use OWL/RDFS i'm automatically in the
SW context (SWC) ? i think i can agree with that, but let me ask a more
precise question :
                        - Do you think that a use case (i don't want to
use the word application) where somebody uses OWL ontologies without
REASONING TASKS (classification, individuals retrieval, etc...)is still
a SW use case ?
Absolutely!  In fact, I think someone using RDF with no explicit
ontology at all is not only a SW use case, but the most important ones
out there at the moment -- so let's not get too ontology-centric,
although this discussion has gone there (i.e. I haven't seen anyone on
this group mention that RDFS ontologies are being widely deployed and
are covered in the OEP scope)
                        - if yes :
                                this raises a few  very correlated new
questions :
                                - can we make a clear distinction
between an OWL ontology built outside the context of SWC and an OWL
ontology in the SWC ?
I guess it would be possible for using OWL separately from the Web, but
that is sort of like talking about using HTML separate from the Web --
why would you want to?   Seems a pretty borderline case.
                                - Are we able to define two distinct
guidelines, both for OWL but
                                                - one for the more
general OEC (which is clearly not our objective)
                                                - one for the specific
                                - In other word, (it's always the same
question but more precise i think) : what are the differences between
SWC and OEC ?
Again - let's use the Web analogy -- people were building hypertext
books long before Tim BL came along.  He saw an approach where one used
languages and protocols to link these together across computers in a new
way, and the Web was born.   Now, in a certain sense, we could say all
Web applciations are Hypertext apps, but not all hypertext apps are Web
apps -- and, hostory has shown, very little of the pre-Web hypertext
stuff turned out to be the right best practices for the Web -- although
certainly the people from that community who embraced the web were
crucial in helping to identify good Web practices (and some still write
articles today criticizing Tim's design and saying we could have done it
better if we'd stuck with the earlier hypertext designs -- they claim
the web might not be quite as large and society changing, but it would
be designed more cleanly)
                        - if not :
                                to what context does it belong ? the
general Ontology engineering context (OEC) i suppose ? And in this case
do you think that these contexts have such a little intersection in
terms of guidelines that there is no need for us to explore in details
the OEC ?
I think the OEC stuff has been explored in hundreds of papers and books
and is a very rich literature.  I don't see any advantage to my
organization paying W3C fees so that we can participate in a traditional
KR context - we can do that for free in our academic work.   We hope
this WG will concentrate on the work that helps make it easier for
people to understand what the Semantic Web is and how to use it to solve
their real-world problems. 
                        For me the direct consequence of this negative
response is that the very "heavy" criteria (the only one perhaps ) to
definitively distinguish the 2 contexts is  the fact we need/use or not
some reasoning tasks.
Don't you think that by accepting this point of view, which is perhaps
too much restrictive, we could have a simple "bodyguard" or (meta)
guideline or whatever you want which could say to us :
                All the advices, guidelines,...we are going to write
MUST be thought keeping this following final objective in the mind : our
outputs MUST help people to build, in a given context, the best
(distributed) architecture (i.e ontologies could be only a - very
important - part of it) to allow some very specific reasoning tasks.
I'm afraid that taking this point of view means that we have to kwow for
the overall SWA lifecycle all the points which can have a real impact in
REASONING capabilities. It's a hard work but perhaps that it is easier
than the problem to say if this point or this point has to deal with OEC
or SWC ?
You will have understood that, my personal point of view is to make such
simplification in our approach. Not perhaps this one exactly which is, i
must admit, very very restrictive (and perhaps false ? glurps!!!) but
which has the merit to define precise criterias to select the point to
I sort of like the direction you're going, but I am not sure "reasoning
tasks" captures it -- in particular, if I use a couple of inferences
based on OWL in FOAF (for example, by making email addresses
inversefunctional FOAF is able to tell information that is about the
same person when gathered from different "Knows" relations )  is this
"reasoning"?  It does seem to me to be Sem Web and it does use a little
inferencing, but it is definitely not classification, etc. 
Also, I don't think that something that uses a DL reasoner to classify
data elements it is finding in RDF data would not count as a Sem Web
application just because it uses a reasoner.
However, I would agree that soemthing that uses a reasoner to help
create OWL ontologies is not inherently a DL tool in itself (i.e. it
doesn't necessarily "embrace the Web nature of OWL") but that is sort of
like saying a browser is not really part of the Web since it only
displays the hypertext -- it's a true statement in some sense (and
browser design is very different than Web page design) but it doesn't
make that much sense to consider HTML design and use without some idea
of browsers in mind
What I do agree with the most in the above is that we need to explicate
the life cycle of
Thank you very much
best regards
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 Saturday, 17 April 2004 00:25:27 UTC