Dear Pavithra, You have captured the essence of the problem. I do not mean to interfere with this. However, A person can be a child, boy or a man. The same person can not be all three at the same time. In Venn Diagram, those three circles do not intersect. ( mutually exclusive?) However the same boy can grow into a man after a period of time. But Venn diagram is drawn with an assumption, that it represents information for a point in time. The age of a person determines if that person is a child, boy or a man. In Ontology "age" is an attribute of a "Person", you can also have another attribute called " stage or phase" or something that has values child, boy or man. Or age can be used to determine whether he is a child, boy or a man. Subtypes stages of a person to capture age specific behavior / attributes. [MW>] Yes. Child, boy or man subtype stages Of Person, not person. But it is the same person at different point in time.. ( 3D and 4D concepts can help ..?) [MW>] Quite. That is the Person they are stages of. Regards Matthew
Thanks,
Pavithra
Dear Pat,
Can I ask you to do an experiment with Venn diagrams.
Take a piece of paper and draw a circle, label it child, and place (say)
three labels inside: C1, C2, C3. Now draw another circle, label it man, and
draw three labels inside, M1, M2, M3. Now, if each child is a person, and
each man is a person ( which is what subtype/supertype means) then you can
draw a circle round your first two circles and label it person.
The problem is that C1 grows up to be M1, and C2 to be M2 and C3 to be M3,
so you probably want to say that they are the "same" person, but we have
two.
You can try this the other way round. Draw a circle, name it person, with
three labels, P1, P2, P3. Now draw a circle round the subtype that is the
children, and another one that is the men.
Do you still think that the relationship between child and person is
subtype/supertype? (There is a relationship, it just is not
subtype/supertype).
Regards
Matthew
Matthew,
It seems from your earlier post that 'StateOfPerson' is a class of time
slices of Person, and 'Boy' is a subclass of 'StateOfPerson'. That works
logically, but most languages adopt the view of objects as endurants, and in
that view, 'Boy' would be a subclass of 'Person', meaning that every
instance of 'Boy' is an instance of 'Person'. It is true that 'Boy' is also
a Role of a person, which has a finite time extension. That view can be
accommodated in an endurant (3D) ontology. My concern, as I mentioned
before, is to keep the ontology as close as possible to linguistic usage,
and that can be done in 3D with clean logical relations, when one
distinguishes the different meanings that a word may take in different
contexts.
For some specific applications a strictly 4D ontology may work fine. We can
of course create translations from 3D to 4D and back when needed. I just
prefer to work in 3D because it seems easier to create labels that serve as
better mnemonics to help the user to recall the intended meaning. Making
an ontology easy to use is to me an important goal.
Pat
Patrick Cassidy
MICRA Inc.
cassidy@xxxxxxxxx
1-908-561-3416
>-----Original Message-----
>From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx [mailto:ontolog-forum-
>bounces@xxxxxxxxxxxxxxxx] On Behalf Of Matthew West
>Sent: Wednesday, February 12, 2014 8:29 AM
>To: '[ontolog-forum] '
>Subject: Re: [ontolog-forum] Person, Boy, Man > >Dear Patrick, > >Up
to now I have assumed (perhaps incorrectly) that a "time slice" of
>something refers to a time slice of an individual.
>[MW>] That is correct.
>But "man" and "boy"
>are classes, not individuals, and I need clarification from the experts as
to >whether a "time slice" can really be a class? In what formalism is
that not >possible?
>[MW>] Well individual is also a class, man and boy are just classes whose
>members are timeslices of some person.
>
>If an ontology is to be used in Natural Language Processing (a critical
>application, IMHO), then it should diverge from linguistic usage only where
>necessary. I agree that language has some aspects that do not translate
well >into the logical format of ontologies, but the subclass relation of
"boy"
to
>"person" seems very well established in ordinary usage, and if any
ontology >formalism cannot represent that relation, I do not see much of a
future for >that formalism.
>[MW>] We say that a man is a person, but this is very ambiguous. There are
>at least three interpretations of "is a" and we usually leave the
distinguishing >pieces out:
>
>1. "Matthew is a person". This is a classification relation, and should
more >fully be stated "Matthew is an instance of person."
>2. "A female is a person". This is a subtype relation, and should more
fully be >stated "Each female is also a person", or "female is a subtype of
person".
>3. "A boy is a person". This is a temporal part relation and should more
fully >be stated "Each boy is a state (or stage, or part of the life) of a
person".
>
>One of the problems with language is that we leave out as much context as
>we think we can get away with, and sometimes find we have left out too
>much.
>
>Regards
>
>Matthew West
>Information Junction
>Mobile: +44 750 3385279
>Skype: dr.matthew.west
>matthew.west@xxxxxxxxxxxxxxxxxxxxxxxxx
>http://www.informationjunction.co.uk/
>https://www.matthew-west.org.uk/
>This email originates from Information Junction Ltd. Registered in England
>and Wales No. 6632177.
>Registered office: 8 Ennismore Close, Letchworth Garden City,
Hertfordshire,
>SG6 2SU.
>
>
>
>Pat
>
>Patrick Cassidy
>MICRA Inc.
>cassidy@xxxxxxxxx
>1-908-561-3416
>
>
> >-----Original Message-----
> >From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx [mailto:ontolog-forum-
>>bounces@xxxxxxxxxxxxxxxx] On Behalf Of doug foxvog > >Sent: Tuesday,
February 11, 2014 4:49 PM > >To: [ontolog-forum] > >Subject: Re:
[ontolog-forum] Person, Boy, Man > >On Tue, February 11,
>2014 15:13, Ali H wrote:
> >> On Tue, Feb 11, 2014 at 2:48 PM, John McClure >>
><jmcclure@xxxxxxxxxxxxxx>wrote:
> >
> >>> Take a Person for example, with subclasses Boy and Man.
> >*[MW] The main
> >>>> problem with this is that Boy and Man are not subtypes of person.
> >>>> For Boy and Man to be subtypes of Person, each Boy is a Person, and
>>>>> each Man is a (different) Person.
> >>>> What would be correct is that Boy and Man a subtypes of >>>>
>StateOfPerson, and that each StateOfPerson is a temporalPart of a >>>>
>Person.* > >This is forcing a 4D view on those who don't wish to use it.
> >
> >Instead of claiming one model is (in)correct, it would be nicer to say,
"In the >>4D model, non-rigid classes such as Boy and Man, are not subtypes
of rigid >>classes such as Person. A 4D model would consider Boy and Man
to be >>subtypes of a non-rigid StateOfPerson, and ..."
> >
> >>> To most people, and dictionaries, Boy and Man are subtypes of Person.
> >
> >The relation "subtype" means that any instance of the first thing are
>>instances of the second thing. In 4D a Man or Boy is a time slice of a
>>MalePerson.
> >For
> >someone using 3D(+1) at any time there is an instance of a Man or Boy,
>that >instance is also an instance of Person.
> >
> >>> Second, should a KB contain both a Boy & Man resource about a given
>>>> individual, owl:sameAs would be used to indicate their equivalence
>>>> >>> >otherwise, yes, they would be a different person, as they should
be.
> >
> >If Man & Boy were defined as disjoint, then nothing could simultaneously
>be >an instance of both. But something could in one context be an
instance >of >one and in another context be an instance of the other.
> >
> >> First, you might want to take a look at the Ontoclean paper [1],[2].
> >> In this view, Boy is not Rigid, and hence not recommended to be >>
>related to a Person via a subtype relationship.
> >
> >All this means is that Ontoclean promotes a 4D view. If this is merely
a >>recommendation it does not require 4D.
> >
> >>> Third, StateofPerson is a wholly artificial term, lacking both >>>
practical >merit and semantic credibility. Fourth, this is a fine >>>
example of >ontologists' implicit saintliness modelling 'concepts' not
>>'language'.
> >
> >> Secondly, from your posts to this forum, this (the privileging or >>
>equating ontology to language) seems to be a major point of departure >>
>from your perspective and (I suspect) many ontologists on the list.
> >
> >I agree. Language can inform ontologies but they are quite different.
> >
> >If computer ontologies were originated by speakers of a language that
>>differentiates "is currently" from "is necessarily", that distinction
>>would >be >part of the ontology language. There would be classes which
instances >are >necessarily members of, and classes which instances may be
members >of for >part of their existence (of which subclasses would be
necessarily > >(non) > >initial, necessarily (non) final, and those which
an instance can join and >leave >multiple times). It would also probably
have resulted in three or >more >subclass/subtype relations: one between
rigid classes, one between
>non- >rigid and rigid classes, and one (or more) between non-rigid
classes.
> >
> >-- doug
> >
> >> Langauge and
> >> ontology *are not* the same things. While language may contain many
>>> clues as to how ontologically model something, it is only that - a clue.
> >> ...
> >
> >> I suspect the majority of ontologists have come to at least the >>
>following conclusions:
> >>
> >> 1. Ontology != Language
> >> 2. There are serious limits to linguistic clues in building an
> >> ontology ...
> >
> >> Best,
> >> Ali
> >>
> >
> >
> >
>
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