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Re: HP reactions to AS&S and OWL

From: Jim Hendler <hendler@cs.umd.edu>
Date: Tue, 14 Jan 2003 16:58:05 -0500
Message-Id: <p05200f49ba4a3447aac5@[]>
To: Jeremy Carroll <jjc@hplb.hpl.hp.com>
Cc: webont <www-webont-wg@w3.org>

>>I'm confused Jeremy - we saw ample examples of implementation of 
>>OWL tools at the f2f, and I'm still not sure what features of Lite 
>>you believe are unimplemented.  I asked several times at the f2f 
>>for people to bring up things they think are as yet unimplemented 
>>but needed for moving to PR, and very few were mentioned - my lab 
>>took two actions to produce some of this.  You brought up none and 
>>volunteered none.  I have been drafting some starts at the 
>>implementation experience, and I don't see any major holes -- 
>>please identify any you have so we can start to fill them
>Currently noone has a complete OWL Lite reasoner.
>I have every reason to believe that NI will deliver one, but that's 
>one rather than two.
>If OWL Lite is meant to be easy, and a trustworthy basis for 
>interoperability then we should be looking at more than one complete 
>OWL Lite reasoner before exiting CR.

do you mean only Lite?  Does Euler fail any of the Lite tests at this 
point?  I was under the impression from something Jos said that he 
handled virtually all the Lite tests - did I misunderstand?

>Also I am dubious that full tools that incompletely support lite 
>will give the sort of interoperability that wg members were looking 
>So to justify its existence Lite not only needs to be implemented, 
>but we should get the feeling that almost all OWL tools will migrate 
>to having complete OWL Lite capability. My colleagues are more 
>doubtful of this than I am.

First - I understand that you have a tools focus, and will ask the 
following about tools:
  I don't understand the "...almost all OWL tools will might to having 
COMPLETE OWL Lite capability" -- I would expect almost all OWL tools 
to support the bulk of the Owl Lite functionality, but would be very 
surprised if very many of them are complete.  This is because I 
expect OWL Lite to be the sublanguage of choice to be supported by 
NON-REASONING tools (like many of those we saw demoed at the f2f) - 
for example, almost all the tools converting from DAML do only some 
subset of Lite - but that is because they are for markup, crawling, 
parsing, querying, etc.  etc -- and none of those promise to have a 
COMPLETE reasoner, since most only use simple reasoning to make the 
tools more powerful.

I believe the above motivates LITE just as much, if not more, than 
the sort of migration you discuss.

However,  probably more importantly - I actually never thought OWL 
Lite was as important for tools as it is for Documents - most of the 
existing DAML ontologies are in or near the OWL Lite coverage -- and 
thus I expect most ontologies for the near future to be in Lite. 
Teaching students to build Lite ontologies is easier, for me, than 
teaching them the more complex DL constructions, and gives them 
access to a lot of power.  Ian often stated that the only motivation 
for Lite was ease of implementation, but many of us never agreed with 
that motivation - and felt ease of exposition and learning to be 
important as well.

So let's not be totally tool-centric, from a document-centric 
perspective (and what is the web if not document-centric?) there's a 
lot of evidence that people will use Owl Lite.

(to confirm the above, [1] is a list of every OWL language construct 
and which ontologies use them.  Playing with that you can find that 
most of them are only using stuff from Lite.  The documents 
themselves may be missing some assertions needed to make them 
stickered Owl Lite documents, but those can be added in conversion - 
can't fault the DAML documents for not generating to an abstract 
syntax that didn't exist when they were written.)
[1] http://www.daml.org/ontologies/features

>I volunteered no tools because within the time frame requested it is 
>unlikely that HP will be able to deliver any. That does not mean 
>that we are not working on OWL. If the wind blows in our favour we 
>just might have a version of Jena with OWL support in it, (i.e. a 
>programming environment which processes imports and allows RDF/XML 
>to be manipulated using the abstractions from OWL).

that would be great, but I do understand that you may not be able to 
do this on time - I didn't mean to criticize you for not 
volunteering, I just meant that at the time you didn't pose that 
there were outstanding implementational items needed.

>If you can circulate a draft of the implementation report I would like
>to ask my colleagues for their comments.

it certainly won't be ready for circulation until after we go to LC. 
At this point I'm gathering data, but all my WG time is spent working 
documents, agendae, etc. until we get the LC documents out the door.


Professor James Hendler				  hendler@cs.umd.edu
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	  240-731-3822 (Cell)
Received on Tuesday, 14 January 2003 17:01:52 UTC

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