W3C home > Mailing lists > Public > public-rule-workshop-discuss@w3.org > June 2005

Re: NAF v. SNAF - where is this being addressed?

From: Jim Hendler <hendler@cs.umd.edu>
Date: Wed, 29 Jun 2005 14:39:55 -0400
Message-Id: <p06200722bee89a3106c3@[172.31.0.192]>
To: Michael Kifer <kifer@cs.sunysb.edu>
Cc: public-rule-workshop-discuss@w3.org
At 14:28 -0400 6/29/05, Michael Kifer wrote:
>Jim,
>
>Yes, the charter must include this.  But I am not sure which charter is
>being discussed. A particular document or in general?
>
>
>	--michael 
>

my understanding is that there is discussion of creating a W3C 
working group to look at creating a rules language (maybe semantic 
web rules language), and that this mailing list is the place for that 
discussion.  The specifics of what goes in a charter is spelled out 
in the W3C process document [1].  Other standards organizations 
probably have other guidelines, but it wouldn't be very sporty to 
discuss some other approach on a W3C mailing list :-)
  -JH
p.s. fwiw, I can testify from my OWL experiences that there are other 
organizations where it is a lot easier and faster for something to 
become what is called a standard, but the credibility and buy-in 
needed to become a W3C Recommendation makes the uptake and visibility 
of a recommendation MUCH higher and is worth the pain.



[1] http://www.w3.org/2004/02/Process-20040205/groups.html#WGCharter

>
>>  Mike - I didn't say that SNAF was controversial.  But it also cannot
>>  be theoretical in the output of a Working Group (the context of my
>>  email) -- an eventual charter has to include specific wording that
>>  addresses this goal -- let me explain using examples from the Web
>>  Ontology Group Charter that eventually led to OWL -- this charter is
>>  in http://www.w3.org/2002/11/swv2/charters/WebOntologyCharter
>>
>>  i. If there is a generally agree upon approach with a well-understood
>>  semantics and a web-realizable syntax, then the charter should
>>  specify this as a starting place
>>        (for example, the Web Ont Charter stated that we must start from
>>  DAML+OIL).
>>  ii.  If there isn't, then the specific goals of the mechanism to be
>>  developed has to be stated (for example, the Web Ont charter
>>  specified with respect to semantics that it must "clearly delineate
>>  what is, and is not, entailed from any particular language construct
>>  or combination thereof")
>>
>>  So, in thinking about creating a working group, I am a bit confused
>>  as to where we stand with this -- I know it is possible to do
>>  something SNAF related, but now we must take it to the next level.
>>    -JH
>>  p.s. Mike, let me use an example that might help you -- in the paper
>>  you and Subrahmanian did, you proved all sorts of great things about
>>  annotated logics.  However, if we were goign to do a standardization
>>  of a particular annotated logic, we would have to be much more
>>  specific and define a particular annotation set and corresponding
>>  logic.  Your paper proves this could be done, and that it should be
>>  done, but doesn't outline the specifics, so a charter would need to
>>  limit the design space to the maximum degree (which is the goal of a
>>  WG charter, and what makes them so danged hard to write)
>>
>>
>>  At 12:20 -0400 6/29/05, Michael Kifer wrote:
>>  >>  All, forgive me if I missed something since I wasn't able to attend
>>  >>  the workshop.  My understanding from the workshop report, and from
>>  >>  discussion with Tim BL and others afterwards, was that NAF wasn't
>>  >>  going to make sense, but SNAF would -- that is, on the Web, if there
>>  >>  is not a mechanism for defining the "KB" (graph) that a set of rules
>>  >>  is applied to, there's not way to use a geenralized negation as
>>  >>  failure -- i.e. I cannot say to the "whole web" that someone can be
>>  >>  assumed to have two children unless it is shown they have a different
>>  >>  number.  Instead, I need a way to designate the dataset that a rule
>>  >>  like this is applied to.  SNAF, as I understand it, was the term
>>  >>  being used to designate this.
>>  >
>>  >Jim,
>>  >Yes, SNAF is a generalization of NAF, and many people (including 
>>me) mean SNAF
>>  >(some prefer to call it scoped default negation) when they say NAF.
>>  >
>>  >
>>  >>    Yet, reading just about all the mail since the workshop, I haven't
>>  >>  seen this referred to at all (and it's not really discussed in the
>>  >>  WRL vs. SWRL or other threads currently being discussed in rdf-rules
>>  >>  and sws-ig)
>>  >
>>  >Some systems, like FLORA-2, inherently support SNAF. WRL was supposed to
>>  >have SNAF, but not in 1.0. This is work in progress. SWSL-Rules will also
>>  >have SNAF, but not in 1.0. (These two languages are actually quite close to
>>  >each other.)
>>  >
>>  >>    Seems to me if I see your rule set includes a NAF-based rule, and
>>  >>  you give me a conclusion to something, that if I don't know what
>>  >>  graph/KB/DB that was applied to, then I have no way to know whether I
>>  >>  can use your result in my application
>>  >
>>  >Note that SNAF applies not only to data sets, but also to rulesets.
>>  >
>>  >>     Seems to me also that this has a big effect on the charter, as I
>>  >>  don't know if there is an agreed upon use of SNAF for the Web, and
>>  >>  would need to be something the WG would be required to elucidate.
>>  >
>>  >SNAF is non-controversial, I think. It is a simple extension of NAF.
>>  >
>>  >
>>  >	--michael
>>  >
>>  >>    -JH
>>  >>  p.s. Note that in datalog, there is always the assumption that the
>>  >>  rules and a particular database can be linked - on the Web, that is
>>  >>  not necessarily true.
>>  >>
>>  >>  --
>>  >>  Professor James Hendler			  Director
>>  >>  Joint Institute for Knowledge Discovery		  301-405-2696
>>  >>  UMIACS, Univ of Maryland			  301-314-9734 (Fax)
>>  >>  College Park, MD 20742
>>  >>http://www.cs.umd.edu/users/hendler
>>
>>  --
>>  Professor James Hendler			  Director
>>  Joint Institute for Knowledge Discovery		  301-405-2696
>>  UMIACS, Univ of Maryland			  301-314-9734 (Fax)
>>  College Park, MD 20742 
>>http://www.cs.umd.edu/users/hendler

-- 
Professor James Hendler			  Director
Joint Institute for Knowledge Discovery	 	  301-405-2696
UMIACS, Univ of Maryland			  301-314-9734 (Fax)
College Park, MD 20742			  http://www.cs.umd.edu/users/hendler
Received on Wednesday, 29 June 2005 18:41:53 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 8 January 2008 14:16:21 GMT