Re: question on domain

Peter F. Patel-Schneider wrote:
> From: Frank Manola <fmanola@acm.org>
> Subject: Re: question on domain
> Date: Fri, 21 Apr 2006 09:51:21 -0400
> 
>> Johnson, Matthew C. (LNG-ALB) wrote:
>>> Hello,
> 
> [...]
> 
>>> Based on my understanding, one can define a property and then specify 
>>> the domain for that property which is the list of classes in which that 
>>> property is allowed.  
>> Not quite.  As several other responders have noted, specifying the 
>> domain doesn't *disallow* use of the property with instances of other 
>> classes.  What it does is license inferences about what classes your 
>> instance is also a member of, based on the domain declaration.  You are 
>> free to disregard those inferences if you don't think they are 
>> appropriate.
> 
> Huh?  Do you actually mean that you can legitimately use RDF(S) and ignore
> the meaning its constructs?  
> 

Well, let's take the original example.  Someone (X) specifies a property 
hasName with domain Person.  Later, someone else (Y), specifies a class 
Pet and decides to "borrow" the original hasName property for use in 
giving names to instances of Pet, e.g.,

ex2:fido rdf:type ex2:Pet  .
ex2:fido ex1:hasName "Fido"  .

The domain specification licenses the inference that

ex2:fido rdf:type ex1:Person .

Y, knowing that she/he borrowed a property with a domain declaration 
that would produce this result, and deciding that it's inappropriate in 
Y's application, chooses to ignore it.  I would argue that:

a.  assuming Y is fully aware of what's going on, no awful sin has been 
committed

b.  this is not "ignoring the meaning of an RDFS construct", this is 
ignoring the meaning that X may have wanted to express in using the 
domain specification (that anything with a name is a person), and that Y 
wishes to generalize

Do you actually mean that someone is bound to treat equally all 
information obtained from any source on the Web, whether that source is 
human or automated inference?

I would imagine that there will be all sorts of cases where, when 
merging information found on the Web, a certain amount of 
"interpretation" of the results will be necessary.

--Frank

Received on Friday, 21 April 2006 14:34:53 UTC