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Re: [ontolog-forum] Ontology similarity and accurate communication

To: <ontolog-forum@xxxxxxxxxxxxxxxx>
From: <matthew.west@xxxxxxxxx>
Date: Thu, 13 Mar 2008 18:15:37 -0000
Message-id: <808637A57BC3454FA660801A3995FA8F06A2D061@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>
Dear Pat C,    (01)

> Matthew,
>   Thanks for the info on the ISO 15296 process.
>   I will answer two questions here:
> [[[1]]]
> > 
> > MW: Please explain how having temporal parts is compatible with not
> > having temporal parts.
> >
>     Because the thing that has temporal parts (the 4D object) 
> is not the
> same type of thing as the one that has no temporal parts (the
> dimension-neutral 'object'), in my own ontology, and 
> different relations
> apply to the two.    (02)

MW: OK then, so you do agree that one pump would be represented twice
(at least). One of the points I have been trying to make is that AN
ontology should be canonical, i.e. it should say anything only once.
This is a simple matter of efficiency. By accepting a 3D and separate
4D representation you are saying the pump exists twice. You need to do
this so you do not mix up 3D statements and 4D statements about it
which would probably be contradictory. I agree you can do this, but as
far as I am concerned we are now dealing with two ontologies and a 
mapping between them. I only really need half of this to do anything
useful.    (03)

>     Alternatively, if a 3D object is considered as a timeslice of a 4D
> object,     (04)

MW: Which timeslice? The 3D object will be coincident with all of them as
it passes through time...    (05)

> it *might* be included in the 'hasTemporalPart' 
> relation, but in
> that case it would trivially be a temporal part of itself, 
> and the relation
> would in fact apply. If the relation's intended meaning were 
> more explicitly
> a necessary 'hasTemporalProperParts', then a time-slice of 
> zero duration
> would *not* be part of the domain of the relation.  I would 
> have to see the
> explicit axiomatization to determine why there is an apparent 
> contradiction.    (06)

MW: What I mention above is a much bigger problem for you.
>    I have seen and participated in enough of these types of 
> discussions to
> know that talk of "logical contradiction" cannot be resolved 
> unless the
> axioms that explicitly demonstrate the logical contradiction 
> are presented.
> Pat Hayes has done that, and I believe that I recognize the 
> flaws in those
> demonstrations, but I will not have time to write the reply 
> for another few
> days.  Hold off on this topic until then?    (07)

MW: Fine
> [[[2]]]
> > 
> > MW: It is only one case. However, what is clear here is that
> > you are shifting your ground to accepting that to get general
> > agreement you would need to include a number of ontological
> > foundations, and the mappings between them where these could
> > be constructed. This IS John's lattice of theories, so he will
> > be pleased to hear that you support his position after all.
> > 
> > MW: You can work out what most of these would be
> > from the commitments they make to e.g. 3d/4d, extensionality
> > and so on. I would guess there might be as many as 10 that
> > would get enough support to be worth pursuing. But you can be
> > open about this, be prepared to include anyone that is prepared
> > to do the mapping work to the n other views (unless one turns
> > out to be able to support all others completely.
> > 
> > MW: Now this I think is worth trying to undertake. But we are
> > now a million miles from a limited vocabulary able to define
> > anything you want.
> >
>    I think we need to revisit a point of terminology.  If an ontology
> includes multiple logically consistent viewpoints that can 
> each be extracted
> for separate use in an application, I consider that to be one 
> ontology.      (08)

MW: I accept that you can take that view too, so I agree we need
to be a bit more precise. What I mean is a canonical ontology.
What you mean is a kind of lattice of theories, but I agree not
necessarily as liberal as JS might allow.    (09)

> The
> separately extracted ontologies are indeed different 
> ontologies, but by
> being extracted from a single logically consistent ontology 
> rather than
> developed separately they will be automatically logically 
> consistent with
> each other (cannot generate contradictions on inferencing), 
> and will be
> highly interoperable. Call that a "mapping" if you like 
> ("mapping" usually
> refers to the process of relating separately developed 
> ontologies).  I would
> have no problem in calling the ontology with multiple views a 
> "lattice of
> theories" except for one point - as it has been used many 
> times, a "lattice
> of theories" can include logically contradictory assertions.      (010)

MW: Strictly a lattice includes all the possible assertions
independently, the question is which combinations you combine, and
how. You are interested in the (some) non-contradictory subset.
I think...    (011)

> If the
> logically consistent ontology with multiple views is a 
> "lattice of theories"
> then it is one of a very special kind, and the distinction 
> must be very
> explicit to avoid confusion.  If you like, call it a "fully consistent
> lattice of theories" - then I am comfortable.    (012)

MW: That sounds OK to me.    (013)

>    I have said on several occasions that I endorse the notion 
> of having a
> "lattice of theories", including logically incompatible ones. 
>  But I still
> believe that there is a self-consistent foundation ontology 
> that includes
> multiple views, which has enough basic concept 
> representations to provide
> the logical specifications of almost all the concepts in any 
> domain - and
> can be supplemented as required to specify any remaining 
> concepts in that
> domain not able to be specified by the pre-existing 
> foundation ontology.    (014)

MW: Maybe, but then it is not canonical, which is a very desirable
practical property.    (015)

> And this is precisely right in the center of my 'limited vocabulary'
> (Conceptual Defining Vocabulary) hypothesis.    (016)

MW: Actually the limited vocab bit is much more contentious, except 
any ontology will naturally be limited.    (017)

>   I have said as part of this hypothesis that the required 
> supplementation
> for any given domain will be small, once the basic CDV is on 
> hand.  But that
> is also part of the hypothesis, which needs to be proven 
> (probabilistically
> - it can never be absolutely proven) by a serious attempt to 
> build such a
> foundation ontology.  And then by applying it to multiple domains.    (018)

MW: As long as you are not insisting on there being no supplementation,
(which I had understood) then you are safe, and indeed, there are lots
of things that can be reused across domains - that is what upper and
mid-level ontologies are for. But now we are a long way from 6000
perhaps reducing to 4000, we are on a steadily climbing curve without
an asymtote.    (019)

Regards    (020)

Matthew West
Reference Data Architecture and Standards Manager
Shell International Petroleum Company Limited
Registered in England and Wales
Registered number: 621148
Registered office: Shell Centre, London SE1 7NA, United Kingdom    (021)

Tel: +44 20 7934 4490 Mobile: +44 7796 336538
Email: matthew.west@xxxxxxxxx
http://www.matthew-west.org.uk/    (022)

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