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Re: [OEP] Other QCR approaches

From: Christopher Welty <welty@us.ibm.com>
Date: Fri, 10 Jun 2005 16:45:08 -0400
To: Aldo Gangemi <aldo.gangemi@istc.cnr.it>
Cc: public-swbp-wg@w3.org, public-swbp-wg-request@w3.org
Message-ID: <OF1AF18953.AF400AD9-ON8525701C.0070ADE9-8525701C.0071FB4D@us.ibm.com>

public-swbp-wg-request@w3.org wrote on 06/09/2005 02:57:15 PM:
> 4) decouple a DAML+OIL-like typed QCR into allValuesFrom + OWL QCR. This 
is not 
> applicable to any of Alan's use cases btw, but only in simpler cases. 
For example:
> 
> A typical date (as a meeting btw two prospective lovers) has exactly two 
participants ->
> 
> Class(TypicalDate
>     subClassOf(Restriction(
>       hasParticipant) cardinality(2)))
>     subClassOf(Restriction(
>       hasFinger allValuesFrom(Person))))

Assuming you mean "hasParticipant" instead of "hasFinger" (which would be 
a very atypical date indeed), I have no idea what you are claiming here. 
This is just a regular allvaluesfrom restriction.  QCRs come into play 
when you want to say something like a "typical date has exactly two 
participants and exactly one is male and exactly one is female".  Your 
example, at least, does not demonstrate QCRs at all.

> I also apply sometimes a reified approach:
> 
> 5a) reify cardinality as a property, for example:
> 
> DatatypeProperty(reifiedCardinality
>    range(xsd:int))
> 
> Class(NormalHand
>     subClassOf(Restriction(
>         hasPart someValuesFrom (intersectionOf
>          Finger
>          Restriction(
>           reifiedCardinality oneOf(5)))))

do you mean oneOf(4)?

>     subClassOf(Restriction(
>         hasPart someValuesFrom (intersectionOf
>          Thumb
>          Restriction(
>           reifiedCardinality oneOf(5))))))

do you mean oneOf(1)?

Why would you do this?  You get nothing from it other than a way to "hide" 
the QCR from OWL completely.  You would have to build your own inference 
engine that knew something about this kind of cardinality.  You can't 
write axioms in OWL to give you the behavior you want, and you couldn't 
conclude with a standard OWL reasoner, for example, that a hand with four 
fingers and a thumb is a normalHand.

> 5b) reify cardinality as a property, and reify the Q(C)R as a class, for 
example:
> 
> Class(NormalHandedness
>     subClassOf(Restriction(
>       settingFor someValuesFrom(intersectionOf
>        Hand
>        Restriction(
>         hasPart someValuesFrom(Finger)
>        Restriction(
>         hasPart someValuesFrom(Thumb))
>     subClassOf(Restriction(
>       settingFor someValuesFrom(intersectionOf
>        Finger
>        Restriction(
>         reifiedCardinality oneOf(5)))))
>     subClassOf(Restriction(
>       settingFor someValuesFrom(intersectionOf
>        Thumb
>        Restriction(
>         reifiedCardinality oneOf(5)))))
>     subClassOf(Restriction(
>       settingFor cardinality(6))))

This is totally confusing.  If you really think you have a valid alternate 
approach, can you verify that your example conveys what you intend, where 
did the "6" come from???? What is "settingFor" supposed to denote? 
"Handedness" in (at least US) English refers to which hand is dominant 
(i.e. "right handed" or "left handed").  I assume that is NOT what you 
mean here, but for the life of me I can't tell what you DO mean.

-Chris


> 
> Approach (5b) uses a pattern similar to the approach 2 from the n-ary 
relations 
> note, but it also reifies cardinality restrictions as in (5a).
> In general, I notice that (5b) is more precise than (5a), because it 
separately 
> states the actual exact cardinality for this definition of normal 
handedness. 
> Moreover, other assertions on hands can be made without them impacting 
on the 
> definition of normal handedness.
> The approach in (5b) comes from a more general pattern that can be 
applied to other
> parametric constraints, like time-indexed properties, and many other 
applications. 
> The exemplification with time-indexed properties could be part of a 
dedicated note,
> which I'm proposing in a separate message.
> 
> Sorry for this quick and probably messed-up explanation, but I wanted to 
submit it 
> before the OEP telecon (in five minutes ...).
> Cheers
> Aldo
> -- 

> 
> 
> 
> Aldo Gangemi
> Research Scientist
> Laboratory for Applied Ontology
> Institute for Cognitive Sciences and Technology
> National Research Council (ISTC-CNR)
> Via Nomentana 56, 00161, Roma, Italy
> Tel: +390644161535
> Fax: +390644161513
> also.gangemi@istc.cnr.it
> http://www.istc.cnr.it/createhtml.php?nbr=71
Received on Friday, 10 June 2005 20:45:30 UTC

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