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

From: Umberto Straccia <umberto.straccia@isti.cnr.it>
Date: Wed, 18 Jul 2007 14:57:10 +0200
To: public-xg-urw3@w3.org
Message-id: <18F37153-95CC-46A5-A6EB-EA2484243927@isti.cnr.it>

On Jul 18, 2007, at 2:09 PM, Ken Laskey wrote:

>
> Peter,
>
> Again the question is what is the purpose of our uncertainty ontology.

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.



> I believe the properties you propose may be important as part of  
> our conclusions of what information an _instance_ must eventually  
> convey, but is it necessary in our ontology if we are using that as  
> a guide for classifying descriptive aspects of uncertainty?
>
> As I note in an email I just sent on criteria for proposing OWL  
> extensions, examples of how something would be used are encouraged.
Received on Wednesday, 18 July 2007 13:23:16 GMT

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