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RE: [URW3 public] Re: [URW3] ... three questions based on the last telecon

From: Mike Pool <mpool@convera.com>
Date: Mon, 16 Jul 2007 09:24:24 -0400
Message-ID: <6B1CD4A11E730446897E4715B119338A431778@vnmail.convera.com>
To: <mkokar@vistology.com>, "Giorgos Stoilos" <gstoil@image.ece.ntua.gr>, "Ivan Herman" <ivan@w3.org>
Cc: <Peter.Vojtas@mff.cuni.cz>, "Ken Laskey" <klaskey@mitre.org>, <public-xg-urw3@w3.org>

Thanks, Mitch,

I'm happy to use OWL to do things like representing our uncertainty
ontology and any other simple representation tasks we want to perform.  

I was just trying to say, or perhaps even insist, that if we're trying
to ascertain how, when and where to represent uncertainty for general
implementation in semantic web reasoning, (or more specifically trying
to meet the objectives set out on
http://www.w3.org/2005/Incubator/urw3/charter) we should not presuppose
going in that any existing w3c language suffices and/or is an
appropriate foundation for what we'd like to do.  I don't think I'm
necessarily suggesting anything different than you are.  We can use OWL
for as far as it takes us, as long as we don't assume going in that it
provides a legitimate constraint. (But in practical terms, I'd rather
use something more expressive, even carefully written English, represent
what needs to be represented and then determine afterwards whether OWL
is capable of capturing that.)

(and in terms of having formal semantics, many languages have formal
semantics, but I think the important question is what that buys us for
doing the representational work we need to do for uncertainty
reasoning.)

Mike

-----Original Message-----
From: Mitch Kokar [mailto:mkokar@vistology.com] 
Sent: Monday, July 16, 2007 8:54 AM
To: 'Giorgos Stoilos'; 'Ivan Herman'
Cc: Peter.Vojtas@mff.cuni.cz; 'Ken Laskey'; public-xg-urw3@w3.org; Mike
Pool
Subject: RE: [URW3 public] Re: [URW3] ... three questions based on the
last telecon

I just wanted to add a few words of clarification to the lively
discussion.

1. The URW3 ontology on our web site is in OWL (see
http://www.w3.org/2005/Incubator/urw3/wiki/UncertaintyOntology?action=At
tach
File&do=get&target=Uncertainty.owl). As it is now, it is just OWL-DL.

2. The intent was to have an ontology to annotate use cases, and not to
develop a full ontology for reasoning about uncertainty. If we jump into
the
details, we will loose our focus and will not accomplish our goal.

3. I suggest that we draw the separation line between the annotation of
the
uncertainty of a sentence and what the sentence is about. Other
communities
are working on the latter issue, so I suggest we just focus on the
former. 

4. However, if we want to be at least a little more specific and try to
satisfy some of the concerns that Peter has raised, we could add one
more
property to the ontology, e.g., "includesSentence" whose domain and
range is
Sentence. In that way we could show that a particular sentence is a
complex
sentence that includes other sentences as components, where those other
sentences can have their own uncertainty. If there is support for this,
I
can make changes in the current URW3 OWL ontology.

In summary, although I agree that OWL has (lots of) limitations, I would
rather use a language that has formal semantics, rather than trying to
propose a new language at this point. This might turn out to be
necessary in
the future, but for now I hope OWL is sufficient.


==Mitch


 

   > -----Original Message-----
   > From: public-xg-urw3-request@w3.org 
   > [mailto:public-xg-urw3-request@w3.org] On Behalf Of Giorgos Stoilos
   > Sent: Monday, July 16, 2007 7:55 AM
   > To: 'Ivan Herman'
   > Cc: Peter.Vojtas@mff.cuni.cz; 'Ken Laskey'; 
   > public-xg-urw3@w3.org; mpool@convera.com
   > Subject: RE: [URW3 public] Re: [URW3] ... three questions 
   > based on the last telecon
   > 
   > 
   > 
   > 
   > > -----Original Message-----
   > > From: Ivan Herman [mailto:ivan@w3.org]
   > > Sent: Monday, July 16, 2007 2:33 PM
   > > To: Giorgos Stoilos
   > > Cc: Peter.Vojtas@mff.cuni.cz; 'Ken Laskey'; 
   > public-xg-urw3@w3.org; 
   > > mpool@convera.com
   > > Subject: Re: [URW3 public] Re: [URW3] ... three 
   > questions based on the 
   > > last telecon
   > > 
   > > 
   > > 
   > > Giorgos Stoilos wrote:
   > > > Hi Peter,
   > > >
   > > > Triples syntax is very specific to the RDF standard 
   > and *not* to 
   > > > every
   > > W3C
   > > > standard. For example, triples syntax is not used in OWL (the 
   > > > standard describes a mapping to RDF graphs but a) it 
   > is very limited 
   > > > and cannot capture the OWL Semantics b) other syntaxes are 
   > > > preferred),
   > > 
   > > ??? why is the mapping limited?
   > > 
   > > Also: OWL is not equal to OWL-DL. OWL Full is fully 
   > described and 
   > > defined in terms of an extension of RDF semantics, and 
   > the there is a 
   > > very clear mapping between the OWL DL semantics and the 
   > corresponding 
   > > OWL Full semantics.
   > > 
   > > However: we indeed have to separate two things. There is 
   > a 'syntax', 
   > > essentially RDF/XML, which is nothing more than what it 
   > says: syntax.
   > > And there is the triple model. Indeed, in some cases 
   > other _syntaxes_ 
   > > are preferred. But that is a secondary issue in my view.
   > > 
   > 
   > Sorry, I only had OWL DL in mind. So triples syntax (and 
   > not the mapping) is limited in the sense that when mapping 
   > OWL DL to triples one would require to use roles and 
   > concepts in unusual places, like in the subject or object position.
   >  
   > > >                                                        
   >       while 
   > > > RIF
   > > will
   > > > not care about triples syntax at all.
   > > >
   > > 
   > > This _may_ become correct if you refer to the RDF/XML 
   > syntax. It is 
   > > not correct if you refer to the model of RDF triples.
   > 
   > Is there going to be a "RIF map to RDF graphs"?.
   > 
   > -gstoil
   > 
   > > 
   > > > I think you are mixing two issues here.
   > > > 1) The specification of an uncertainty ontology, which 
   > describes the 
   > > > concepts and their relations, i.e. the schema, i.e. 
   > the TBox. So I 
   > > > don't
   > > see
   > > > why we should add instances (ABox) in the ontology. At 
   > least in my 
   > > > understanding the Ontology is *not* meant to describe 
   > how to capture 
   > > > uncertainty in practice.
   > > > 2) How to extend ontology languages, like OWL, to add 
   > uncertainty. 
   > > > Then
   > > we
   > > > should take into account instances and thus the ABox 
   > and thus your
   > > example
   > > > below has a purpose.
   > > > So I don't understand how reification fits with the Uncertainty
   > > Ontology.
   > > >
   > > > Now, taken that triples are used in RDF (and not in 
   > OWL) I see your
   > > example
   > > > below as an effort to extend RDF as to capture 
   > uncertainty, or about 
   > > > serializing an Uncertainty-OWL extension to RDF 
   > triples, which I 
   > > > don't
   > > see
   > > > how is relevant.
   > > >
   > > > -gstoil
   > > >
   > > >> -----Original Message-----
   > > >> From: public-xg-urw3-request@w3.org [mailto:public-xg-urw3-
   > > request@w3.org]
   > > >> On Behalf Of Peter Vojtas
   > > >> Sent: Monday, July 16, 2007 11:24 AM
   > > >> To: Ken Laskey
   > > >> Cc: public-xg-urw3@w3.org; mpool@convera.com
   > > >> Subject: [URW3 public] Re: [URW3] ... three questions 
   > based on the 
   > > >> last telecon
   > > >>
   > > >>
   > > >> Dear colleaguess (sent to public list and separately 
   > to KL and MP),
   > > >>
   > > >> as I have pointed in the ontology page in Top Level 
   > comments by P.
   > > >> Vojtas is there a mistake?, see
   > > >> 
   > http://www.w3.org/2005/Incubator/urw3/wiki/is_there_a_mistake%3F
   > > >>
   > > >> by W3C standards, basic information unit is a triple 
   > (subject, 
   > > >> predicate, object) which can be true or false in a 
   > structure (to 
   > > >> avoid discussion whether it is a sentence or 
   > proposition, w3c uses
   > > statement).
   > > >>
   > > >> see e.g. http://www.w3.org/TR/rdf-primer/ for 
   > following example
   > > >>
   > > >> http://www.example.org/index.html has a creation-date 
   > whose value 
   > > >> is August 16, 1999
   > > >>
   > > >> here we can use reification for another writing asigning an 
   > > >> identifier to the statement
   > > >>
   > > >> ex:triple1	rdf:type	rdf:Statement
   > > >> ex:triple1	rdf:subject 	
   > http://www.example.org/index.html
   > > >> ex:triple1	rdf:predicate
   > > 	http://purl.org/dc/elements/1.1/creator
   > > >> ex:triple1	rdf:object 	
   > http://www.example.org/staffid/85740
   > > >> ex:triple1	ex:creator	
   > http://www.example.org/staffid/85741
   > > >>
   > > >> THIS CONSTRUCTION IS VERY USEFULL IN OUR CASE
   > > >>
   > > >> especialy in our ontology discussion the triple
   > > >>
   > > >> urw3:Sentence  	urw3:hasUncertainty  urw3:Uncertainty
   > > >>
   > > >> should be by my opinion rewritten as
   > > >>
   > > >> urw3:triple2	rdf:type	rdf:Statement
   > > >> urw3:triple2	rdf:subject 	urw3:Sentence
   > > >> urw3:triple2	rdf:predicate 	urw3:hasUncertainty
   > > >> urw3:triple2	rdf:object 	urw3:Uncertainty
   > > >> urw3:triple2	ex:creator	urw3:Mitch
   > > >>
   > > >> and instance ( consider also an "instance"  ex:triple1 
   > > >> urw3:hasUncertainty  urw3:0.9)
   > > >>
   > > >> as, e.g.
   > > >>
   > > >> urw3:triple3	rdf:type	rdf:Statement
   > > >> urw3:triple3	rdf:subject 	ex:triple1
   > > >> urw3:triple3	rdf:predicate 	urw3:hasUncertainty
   > > >> urw3:triple3	rdf:object 	urw3:0.9
   > > >> urw3:triple3	ex:creator	urw3:Peter
   > > >> urw3:triple3	urw3:tool	urw3:Bayes
   > > >>
   > > >> The example with the german sentence (Mathias can 
   > help) is very 
   > > >> usefull (words morgen and Morgen are problematic) 
   > because it shows 
   > > >> what can happen. MP assigns an uncertainty to his own 
   > translation 
   > > >> by expression "if I've translated correctly". 
   > Nevertheless, by my 
   > > >> opinion "Es regnet morgen" is a problematic sentence 
   > because "Es 
   > > >> regnet" is about present and "morgen" with lower case 
   > m in the 
   > > >> begining means tomorrow, it is an adverb. So a 
   > problem accurs, what 
   > > >> to do with a gramaticaly wrong sentence (note that the word 
   > > >> sentence I use here in the linguistical sense, which 
   > in the W3c 
   > > >> terminology can by defined appropriately by 
   > corresponding triples, 
   > > >> by defining predicates like subject, verb, object, 
   > mode (manner), 
   > > >> place and time). I would say either "Es regnet heute 
   > morgen" or "Es wird morgen regnen".
   > > >>
   > > >> Sorry for such a long mail, concluding I would like 
   > to say, please 
   > > >> let us use w3c terminology (arguing for necessity of 
   > an extensions 
   > > >> of standards we need be compatible with current 
   > standards). Next, 
   > > >> the
   > > above
   > > >> example shows we need to define our own prefix and 
   > rdf vocabulary 
   > > >> for uncertainty ontology.
   > > >>
   > > >> Greetings Peter
   > > >>
   > > >>
   > > >>
   > > >>>     *From:* Mike Pool
   > > >>>     *Sent:* Friday, July 13, 2007 3:25 PM
   > > >>>     *To:* public-xg-urw3-request@w3.org
   > > >>>     *Subject:* three questions based on the last telecon.
   > > >>>
   > > >>>     Hi, all:
   > > >>>
   > > >>>     We've been having some great discussions during 
   > the meetings 
   > > >>> and
   > > I'd
   > > >>>     like to pick up a few threads that came up in 
   > the last meeting.  I
   > > >>>     reread these as I was trying to write up the minutes:
   > > >>>
   > > >>>     1)
   > > >>>     Peter suggested that we use w3c standards as our 
   > guide for the
   > > >>>     meaning of 'proposition'.  Peter, do you know if 
   > this is defined
   > > >>>     somewhere by the w3C.  Could you point us to the 
   > definition?
   > > >>>
   > > >>>     2)
   > > >>>     I argued that propositions, in the sense of the 
   > meaning of a
   > > >>>     sentence that is invariant through all the 
   > paraphrases and
   > > >>>     translations of the sentence, rather than assertions or 
   > > >>> sentences
   > > as
   > > >>>     the kinds of things that hold probability values.
   > > >>>
   > > >>>     Kathy noted in the meeting that a problem with 
   > this definition is
   > > >>>     that a system might assign different uncertainty 
   > values to 2
   > > >>>     different logically equivalent sentences.   I 
   > can imagine that
   > > this
   > > >>>     is possible, but where it occurs I would think 
   > it nothing more
   > > than
   > > >>>     a weakness in the system, not in the definition 
   > I've suggested.
   > > For
   > > >>>     example, I might misunderstand 'Es regnet 
   > morgen' as 'it will rain
   > > >>>     this morning' rather than 'it will rain 
   > tomorrow' (if I've
   > > >>>     translated correctly) and assign it a different 
   > probability value
   > > >>>     than that which I'm assigning to 'it will rain 
   > tomorrow'.  But I
   > > >>>     think that anyone who observed my doing this 
   > would point out that
   > > >>>     it's a contradiction, i.e., that since these 
   > things have the same
   > > >>>     meaning, I'm obligated to assign them the same 
   > probability value.
   > > >>>      In other words, it is in virtue of their 
   > representing the same
   > > >>>     proposition that I'm obligated to assign them 
   > the same probability
   > > >>>     value.    So, I think this only helps to 
   > underscore the fact that
   > > >>>     when we explore our intuitions, we believe that 
   > propositions 
   > > >>> are
   > > the
   > > >>>     real p.v. holders.
   > > >>>
   > > >>>     3)
   > > >>>     Anne, you said at one point that "not all beliefs can
   > > appropriately
   > > >>>     be represented as numerical values" and that it 
   > "glosses over
   > > >>>     inconsistencies - beliefs may be logically 
   > incompatible".  I was
   > > >>>     intrigued by the suggestion, can you say more?
   > > >>>
   > > >>>
   > > >>>     Again, thanks all for a stimulating telecon on Wednesday.
   > > Apologies
   > > >>>     in advance if this address is not the right 
   > forum for these
   > > >>>     discussions.
   > > >>>
   > > >>>     Best regards,
   > > >>>
   > > >>>     Mike Pool
   > > >>>
   > > >>>     --------------------------------
   > > >>>
   > > >>>
   > > >>>
   > > >>> 
   > ------------------------------------------------------------------
   > > >>> ----
   > > --
   > > >> -----
   > > >>> Ken Laskey
   > > >>> MITRE Corporation, M/S H305 phone: 703-983-7934
   > > >>> 7151 Colshire Drive fax: 703-983-1379 McLean VA 22102-7508
   > > >>>
   > > >
   > > >
   > > >
   > > 
   > > --
   > > 
   > > Ivan Herman, W3C Semantic Web Activity Lead
   > > URL: http://www.w3.org/People/Ivan/
   > > PGP Key: http://www.cwi.nl/%7Eivan/AboutMe/pgpkey.html
   > > FOAF: http://www.ivan-herman.net/foaf.rdf
   > 
   > 
   > 
Received on Monday, 16 July 2007 13:32:48 GMT

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