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Re: Case for Reinstatement of Qualified Cardinality Restrictions

From: pat hayes <phayes@ai.uwf.edu>
Date: Thu, 17 Apr 2003 16:07:36 -0500
Message-Id: <p05111b03bac4c713abe7@[]>
To: "Jos De_Roo" <jos.deroo@agfa.com>
Cc: Jim Hendler <hendler@cs.umd.edu>, "Jonathan Borden" <jonathan@openhealth.org>, "webont" <www-webont-wg@w3.org>, www-webont-wg-request@w3.org

>I agree as well.
>Pat, what kind of notation are you using?
>   [minCardinalityFrom P 1]
>   [maxCardinalityFrom [Complement P] 0]
>   [Hand partOf CardinalityFrom Fingers 5]

I made it up, sorry.  I hate description-logic syntax.

>I think that the last one is in N3 like
>   :Hand a owl:Restriction;
>         owl:onProperty :partOf;
>         daml:cardinalityQ 5.
>         daml:hasClassQ :Fingers.

Right, exactly. Typing this stuff makes my knuckles hurt.


>-- ,
>Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/
>                     pat 
>                     <phayes@ai.uwf.edu       To:     Jim Hendler 
>                     >                        cc:     "Jonathan 
>Borden" <jonathan@openhealth.org>, "webont"            
>                     Sent by: 
>                     www-webont-wg-requ       Subject:     Re: Case 
>for Reinstatement of Qualified Cardinality         
>                     est@w3.org 
>                     2003-04-17 
>>At 6:20 PM -0400 4/16/03, Jonathan Borden wrote:
>>>As I recall the discussion at the Amsterdam F2F -- I had wondered if such
>>>features would be needed by biomedical ontologies and thought that I was
>>>told that this wasn't the case.
>>>The use cases he cites are compelling (at least to me), and if indeed
>>>qualified cardinalities *are* needed to support these then I strongly
>>>support reopening the issue.
>I agree. Seems to me that its up to those who think not, to respond
>to Alan's examples with counter-arguments, eg showing that the
>workarounds that he dislikes aren't so bad after all, or that there
>are better ones.
>>I am worried that the feature most complained about in Daml+oil and
>>also the ones most misused were these.
>On the other hand, maybe that was partly due to the truly awful
>terminology used, and the fact that the DAML tutorials placed very
>little emphasis on them. And that this whole ontology thing was new
>to many DAML users, whereas Alan is speaking from a much more
>sophisticated community.
>>Let me make a suggestion -- if we were to decide to include these,
>>we would need to write the one-paragraph, easy to understand
>>explanation that would go in the Overview -- anyone want to take a
>>stab at a suggested one?
>Well, the guide only talks about OWLLite, which has limited
>cardinality in any case so wouldnt work for Alan's examples, but here
>goes as a sketch:
>3.4a OWL  Restrictions
>minCardinalityFrom: This refer to a class and a number. It
>generalizes someValuesFrom by requiring at least that number of
>values for the property to be of the type described by the class.
>Note that this says nothing about values of the property in other
>classes. [someValuesFrom P] is equivalent to [minCardinalityFrom P 1]
>maxCardinalityFrom: this restriction requires that the number of
>values for the property which are of the type described by the class
>be no more than the number given. Note that this says nothing about
>values of the property in other classes.  [allValuesFrom P] is
>equivalent to [maxCardinalityFrom [Complement P] 0]
>CardinalityFrom:  This restriction is provided as a convenience when
>it is useful to state that there is an exact number of values of a
>property in a particular class, eg [Hand partOf CardinalityFrom
>Fingers 5] says that the number of partsOf a Hand that are classified
>as Fingers must be 5.  Note that this says nothing about values of
>the property in other classes; for example, a hand may also have
>parts which are the palm and the back, in addition to the 5 fingers.
>minCardinality:  this restriction simplifies minCardinalityFrom by
>ignoring the class; it simply sets a lower bound on the total number
>of values of the property, in effect treating the restricting class
>to be the universe.  In OWL-DL, [minCardinality n] is equivalent to
>[minCardinalityFrom owl:Thing n] for individual properties and to
>[minCardinalityFrom rdfs:Literal n] for datatype properties; in
>OWL-Full, it is equivalent to [minCardinalityFrom rdfs:Resource n].
>similarly for maxCardinality, Cardinality.
>>   -JH
>>p.s. Any change that would require us to change every document and
>>that is exposed by test cases makes me nervous at this late date --
>>I'd want to see pretty strong support for the change...
>Seems to me that Alan makes a devastating case in favor, and that
>although it is so late and all, that we will look kind of silly if we
>don't take it seriously. I wish I had thought of the atria/ventricles
>example. Particularly as he practically tells us what to do.
>So, I vote to reinstate.
>>>>   The following long message (from [1]) comes from Alan Rector to our
>>>>   comments list, addressing the issue of the qualified constraints -
>>>>   basically, he's asking us to reopen issue 3.2 Qualified Cardinality
>>>>   constraints.  Guus and I would like to hear the WG's feelings on
>>>>   this.  Since there's no specific document addressed (although it
>>>>   would require changes in every document), Guus and I will handle this
>>>>   email and its response.
>>>>     -JH
>>>>   [1]
>>Professor James Hendler
>>Director, Semantic Web and Agent Technologies             301-405-2696
>>Maryland Information and Network Dynamics Lab.            301-405-6707
>>Univ of Maryland, College Park, MD 20742             240-731-3822 (Cell)
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Received on Thursday, 17 April 2003 17:07:40 UTC

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