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Re: WOWG: compliance levels on next teleconf

From: Deborah McGuinness <dlm@KSL.Stanford.EDU>
Date: Wed, 01 May 2002 08:14:38 -0700
Message-ID: <3CD0065E.75FC23EB@ksl.stanford.edu>
To: www-webont-wg@w3.org
CC: Frank van Harmelen <Frank.van.Harmelen@cs.vu.nl>
I also presented our strategy to the EU/US joint committee meeting readout
yesterday.
I reiterated the goals I stated in the email to webont

One possible strengthened criteria for the design of Level 1 was proposed
- attempt to make level 1 cover the needs of a significant number (50-75%)
of our expected user communities.

I am not sure that this can be achieved while maintaining the goals that
frank mentioned below
and the ones i stated in
http://lists.w3.org/Archives/Public/www-webont-wg/2002Apr/0362.html

I grabbed just the goals here
Our small group strategy was to
1 - come up with an agreement on a small language that hopefully many tool
developers will support
2 - attempt to get the most useful features in this small language
3 - keep the small language small - thus we explicitly were not taking the
strategy of including everyone's favorite constructor for which they could
make a
compelling argument.
4 - not penalize too heaviliy tool developers who want to add construct XX
to the
core language.

my goal 2 was a softer version of the goal of covering the needs of 50-75%
of the users.

Frank van Harmelen wrote:

> The discussion on how to define the compliance levels of OWL will be an
> important issue in the next teleconf.
>
> This email is as a preparation for the teleconf.
>
> We should at least decide on how to reach consensus (although I would
> prefer to actually cut some knots during the teleconf).
>
> Frank.
>    ---
>
> 1. The strategy for defining compliance levels at the Amsterdam F2F and
> immediately afterwards was more or less to include any item in level 1
> for which somebody could make a convincing "frequent/common use" case.
> This lead to top-heavy proposals which were hard to justify because
> they  differed only little from full OWL.
>
> 2. A subgroup met at KR'02 in Toulouse, and explored an alternative
> strategy.
> As explained in messages by me, Deb, Ian a.o., the core of the Toulouse
> proposal was
> to identify a language that would be
>
> - easy to implement (thus encouraging toolbuilders)
> - a sufficient step up from RDF Schema (to justify existence)
> - not prejudice the difficulty of any extentions (partly or full) with
> other elements of OWL
>
> This lead to the proposal of "RDF Schema on steroids" as a compliance
> level 1 for OWL (see [1] for what this includes).
>
> 3. Subsequent discussion revealed that various people would like to have
> additional items in level 1 (e.g. cardinalities, local range
> restrictions). Although none of these by themselves would be hard to
> implement, they are all judged to make it hard to add additional
> features because of the way the features interact.
>
> EXAMPLE: an example is local range restrictions. When interpreted as
> existential ("slot S must have at least one value of type T") they are
> easy to implement, similar when interpreted as universal ("all values of
> slot S must be of type T"), but the combination of these two is hard to
> implement. Thus, including either in level 1 will make it harder to
> extend beyond level 1 and include the other. (Different communities seem
> to have different need for either extension).
>
> 4. The minimal required result at the teleconf is that we agree whether
> the "Toulouse approach" is the right one to take.
> If yes, we can argue the details of "RDF on steroids" as level 1
> If no, we must formulate another strategy for defining level 1 (keeping
> in mind that the "Amsterdam F2F approach" has already shown to lead to
> failure).
>
> Please spend some time thinking all this over before the teleconf.
>
> Frank.
>    ----
> [1] http://lists.w3.org/Archives/Public/www-webont-wg/2002Apr/0329.html

--
 Deborah L. McGuinness
 Knowledge Systems Laboratory
 Gates Computer Science Building, 2A Room 241
 Stanford University, Stanford, CA 94305-9020
 email: dlm@ksl.stanford.edu
 URL: http://ksl.stanford.edu/people/dlm
 (voice) 650 723 9770    (stanford fax) 650 725 5850   (computer fax)  801
705 0941
Received on Wednesday, 1 May 2002 11:15:22 GMT

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