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Re: DOCUMENT: Layering document review (was Re: UPDATE: status of longer version of layering document)

From: Jim Hendler <hendler@cs.umd.edu>
Date: Wed, 13 Feb 2002 13:26:28 -0500
Message-Id: <p05101404b8905edc1bec@[10.0.0.18]>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
Cc: www-webont-wg@w3.org
At 12:54 PM -0500 2/13/02, Peter F. Patel-Schneider wrote:
>From: Jim Hendler <hendler@cs.umd.edu>
>Subject: Re: DOCUMENT: Layering document review (was Re: UPDATE: 
>status of     longer version of layering document)
>Date: Wed, 13 Feb 2002 09:39:03 -0500
>
>>  Frank - the problem is that 1-4 as you define them below are
>>  APPROACHES, not yet proposed solutions to move on.  I mean we need to
>>  figure out how we operationalize these approaches and move to
>>  language features that support them.
>
>Well, I believe that there already are proposed solutions using approaches
>2, 3, and 4.
>
>Approach	Proposal
>
>2.Syntax and semantic extension
>
>OWL - 
>http://lists.w3.org/Archives/Public/www-webont-wg/2002Jan/att-0061/01-swol.text
>
>3.Same-syntax, but diverging semantics
>
>DAML+OIL - http://www.w3.org/TR/daml+oil-reference
>
>4.Differing syntax and semantics
>
>OWL' - 
>http://lists.w3.org/Archives/Public/www-webont-wg/2002Jan/att-0061/02-swol.text

(Bad URI, please check)

>What more do you want before having a discussion of which approach to work
>with?

The only one of these currently in a form the WG could actually take 
action is the 2nd, since it is in the form we need to get to and the 
charter says we should use it as a point of departute.  The others 
are still primarily in the form of theoretical contributions, and 
would need work to become actual langauge standards, which is what we 
are producing -- i.e. they need to come out like the second.  These 
are good places to start discussion, but they aren't completed and 
need work - all I'm trying to work out.

>You may note that each of these approaches have (roughly) the same language
>features.  In general, the characteristics of the language do *not* depend
>on which approach is taken.  (Of course, the syntax details of the language
>and the formal specification of the language *do* depend on which approach
>is taken, but both of these can be largely ignored when discussing which
>approach to take.)
>
>>  It is fine and good for the group to decide "We will have a XXX
>>  syntax and YYY semantic extension" (or whatever), but that doesn't
>>  say which things will be the same or different from current DAML+OIL
>>  or why.  We clearly need to set philosophy as part of moving ahead,
>>  but the "task force" I suggested yesterday will need to go through
>>  D+O figuring out how we change it, if at all, to deal with the issues
>>  we've been discussing -- I'm trying to be hard-nosed here and remind
>>  everyone that we need to eventually get this all the way to language
>  > features.
>>
>>    To date, I see nothing that specific on the table, and we need such.
>
>Well, if the two documents I put together were not specific, then I don't
>know what you want.

ahh, i see the problem from the above -- the SYNTAX details are 
critical to the W3C standard we are trying to work out - they're not 
a minor detail to leave up to the implementors.

>
>>  For example - a differing syntax solution could be anything from
>>  "chuck the entire DAML+OIL and start again from scratch using C++
>>  syntax" to "if we simply add the tag <OWL></OWL> around the OWL
>>  equivalent of daml:class statements then everything works again"  --
>>  that's quite a range!  Also, it is complicated by the fact that some
>>  of our reasoning may need to go like this:
>
>>    If RDF were changed to allow XXX then our language works as is (or
>>  with the following minor modification)
>>    if not, then we need to drastically change our language to YYY (for
>>  example, largely abandoning RDF syntax)
>>
>>  which is the best way we could be able to communicate this sort of
>>  thing back to an RDF WG (either Core or future RDF 2.0) for
>>  consideration or joint solution.
>
>It would, I suppose, be possible to state some changes to RDF(S) under
>which each of the approaches could be considered to be an extension of
>RDF(S).

We cannot state changes to RDF(S) (another group's work product), but 
we can recommend such and discuss with those groups to reach some 
sort of joint consensus.

-- 
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)
AV Williams Building, Univ of Maryland		  College Park, MD 20742
http://www.cs.umd.edu/users/hendler
Received on Wednesday, 13 February 2002 13:26:39 GMT

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