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

From: Giorgos Stoilos <gstoil@image.ece.ntua.gr>
Date: Thu, 19 Jul 2007 10:43:11 +0300
Message-Id: <200707190743.l6J7h2u4031801@manolito.image.ece.ntua.gr>
To: "'Umberto Straccia'" <umberto.straccia@isti.cnr.it>, <public-xg-urw3@w3.org>



> -----Original Message-----
> From: public-xg-urw3-request@w3.org [mailto:public-xg-urw3-request@w3.org]
> On Behalf Of Umberto Straccia
> Sent: Wednesday, July 18, 2007 8:55 PM
> To: public-xg-urw3@w3.org
> Subject: Re: [URW3 public] OWL extensions [was Re: [URW3] ... three
> questions based on the last telecon]
> 
> 
> I am more in favor of having no OWL/RDFS language extension at all,
> but encoding the data, according to a core uncertainty ontology,
> which we may develop as outcome (see my previous email.... or just
> below). To my opinion, this is by far much more extensible/flexible
> than any OWL/RDFS language extension and  certainly faster and easier
> to be accepted by any non-uncertainty community.
> 

My point was *not* that your proposal is not feasible. To the contrary it is
very nice. My point was that at the end of the day it will turn our to be
almost (and maybe exactly) the same thing to agree upon using an OWL concept
like LeftShoulderFunction for left shoulder functions, which crisp tools
will have to learn to toss away while fuzzy tools to correctly interpret
compared to having a language (extension) tag like <owlx:
LeftShoulderFunction> which again crisp tools will have to skip while fuzzy
to parse and interpret. 

I think that only after thorough thinking, practical investigations and
practice we could learn which one is better. At this point I see just some
pros and cons for both of them.

Cheers,
-gstoil


> Cheers,
> 
> 	-Umberto Straccia
> 
> 
> %----Straccia's previous email
> 
> The OWL ontology can be used to describe different types of
> uncertainty, but can also to used to describe HOW uncertain
> information is represented in OWL (without any language extension) or
> RDF/RDFS.
> 
> To be explicit, suppose I would like to express the concept of YOUNG
> using an explicit fuzzy membership function such as a left-shoulder
> function with parameter a=20, b=30 (below 20 someone is young to
> degree 1, after 30 he is young to degree 0, in between we use linear
> interpolation).
> 
> Now, we have two options
> 
> a) either we suggest an extension to OWL (more precisely OWL-DL) or
> RDF/RDFS to explicitly accommodate such functions (i.e. we propose a
> language construct for that)
> b) or we develop an OWL-DL ontology (or RDF/RDFS ontology) describing
> HOW to represent such information into the current standardized OWL-
> DL language. In our specific case, we may say that
> 
> LeftShoulderFunction ISA FuzzyMembershipFunction
> 			 WITH HasParameterA of type Float
> 			 WITH HasParameterB of type Float
> 
> 
> Then we can represent Young with
> 
> Young ISA VagueConcept
> 	  WITH HasFuzzyMembershipFunction of type LeftShoulderFunction WITH
> HasParameterA = 20
> 								       WITH
HasParameterB
> = 30
> 
> It is then up to a parser to correctly interpret the statements and
> then to load them into an underlying reasoning system.
> 
> In this way our objective is (using the use cases) to develop an
> ontology, which describes HOW different notions of imperfect
> knowledge is represented in OWL-DL (RDF/RDFS).
> 
> 	-Umberto.
> 
> 
> %----
> 
> 
> On Jul 18, 2007, at 7:30 PM, Giorgos Stoilos wrote:
> 
> >
> > Hi Ken,
> >
> > This sounds reasonable enough. But let me also stress another issue.
> >
> > A proposed extension should be as minimal as possible in order to
> > enjoy
> > acceptance by the non-uncertainty community and persuade people
> > that it
> > could be adopted in their tools with a minimal effort. So also
> > replying to
> > Peter's mail, I do not agree with extensions like
> > owl_ursw:usualy_oneOf,
> > owl_ursw:often_oneOf, owl_ursw:probably_subClassOf, which to me do
> > not seem
> > minimal.
> >
> > -gstoil
> >
> >> -----Original Message-----
> >> From: public-xg-urw3-request@w3.org [mailto:public-xg-urw3-
> >> request@w3.org]
> >> On Behalf Of Ken Laskey
> >> Sent: Wednesday, July 18, 2007 3:02 PM
> >> To: Peter.Vojtas@mff.cuni.cz
> >> Cc: public-xg-urw3@w3.org
> >> Subject: [URW3 public] OWL extensions [was Re: [URW3] ... three
> >> questions
> >> based on the last telecon]
> >>
> >>
> >> Let me make a suggestion of a minimum criteria for adding extensions:
> >>
> >> an extension can be proposed only if you can show its use in the
> >> context of an already discussed use case.
> >>
> >> This is motivated by several thoughts:
> >> 1. we will have solid examples of the extension;
> >> 2. we can more easily compare value of the extension against others
> >> proposed;
> >> 3. we move forward our analysis of the use cases;
> >> 4. if proposed extensions can be demonstrated only in the context of
> >> use cases already discussed, some of you will have the motivation to
> >> volunteer for leading the discussion at future telecons :-)
> >>
> >> Do we have agreement on this proposal?
> >>
> >> Ken
> >>
> >> P.S. per survey results, I will be setting up telecons for August 1,
> >> August 22, September 5, and September 19.
> >>
> >> On Jul 18, 2007, at 7:20 AM, Peter Vojtas wrote:
> >>
> >>>
> >>> Colleagues,
> >>>            let me note that this wonderfull discussion has
> >>> started by
> >>> questions about the nature of "sentence" and "proposition", and I
> >>> have
> >>> added a word used by W3C documents "statement" and as an example a
> >>> triple. Of course a RIF rule can be also a subject to attachment
> >>> of an
> >>> uncertainty.
> >>>      I think this can be satisfactory solved by using current W3C
> >>> standards and interpretation of them.
> >>>
> >>>      Now the problem has shifted a little bit further, to
> >>> ontology. My
> >>> impression is that we need to have some (easy) examples in the
> >>> begining
> >>> (Ken already assigned some sentences in his use case by uncertainty
> >>> type
> >>> and nature).
> >>>      I like Mitch's ontology and so far only few extensions were
> >>> sugested - to have properties includesSentence, isaboutSentence
> >>> and a
> >>> new sort of uncertainty models namely Similarity (maybe some
> >>> other will
> >>> appear later - what are our criteria to enter new elements to
> >>> ontology).
> >>> The reification discussion was only an example from my part, and can
> >>> be soved
> >>> by Uncertainty has_derivation objective/subjective.
> >>>
> >>>      I have also an idea and would like to ask ou for opinion.
> >>> Most of
> >>> Ontological knowledge is described by expressions about being an
> >>> element
> >>> and being a subset (equal to), e.g.
> >>>
> >>> owl:oneOf, rdf:type, ... rdfs:subClassOf, ...
> >>>
> >>> what do you think about extensions like
> >>>
> >>> owl_ursw:usualy_oneOf, owl_ursw:often_oneOf,
> >>> owl_ursw:probably_subClassOf
> >>>
> >>> or we are just going to assign uncertainty to the statement
> >>> A rdf:type B, C rdfs:subClassOf D, ...
> >>>
> >>> I agree that sentences can be structured by logical connectives,
> >>> and I
> >>> would be here very flexible and allow also fuzzy aggregation
> >>> operators.
> >>>
> >>> On the one side we are not going to specify syntax but we have to
> >>> show
> >>> current standards are not necessary (of course not because of the
> >>> syntax of current standards - using W3C syntax we have in mind that
> >>> their semantics does not suffice)
> >>>
> >>> Greetings Peter
> >>>
> >>>
> >>>
> >> ---------------------------------------------------------------------
> >> ---
> >> -----
> >> Ken Laskey
> >> MITRE Corporation, M/S H305      phone: 703-983-7934
> >> 7151 Colshire Drive                         fax:       703-983-1379
> >> McLean VA 22102-7508
> >
> >
> >
Received on Thursday, 19 July 2007 07:43:16 GMT

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