SUO: RE: RE: Problems in SUMO
Julian,
Comments below.
-Ian
> -----Original Message-----
> From: Fowler, Julian [mailto:JFowler@modulant.com]
> Sent: Friday, June 27, 2003 5:43 AM
> To: Patrick Cassidy
> Cc: standard-upper-ontology@ieee.org
> Subject: SUO: RE: Problems in SUMO
>
>
>
> Pat et al
>
> Note the (superficial) similarity between SUMO and EPISTLE -
> the latter's root concept is 'thing', with two mutually
> exclusive subtypes possible_individual and abstract_object.
> There are differences between the two even at this level (see
> the recent discussion between Ian N and Matthew W), so that
> there is no simple mapping SUMO:Physical <->
> EPISTLE:possible_individual. However, in both cases
> developers have found it useful / discovered it necessary to
> start with a very basic decomposition - in the EPISTLE case,
> into things that have spatio-temporal extent
> (possible_individual) and those that don't. The key for
> EPISTLE (and I assume, from a basis of rather less knowledge,
> for SUMO) is that the ontology starts from a world view in
> which it is asserted that everything is a possible_individual
> or it is not (physical or abstract in the case of SUMO), and
> that it is anathema for there to be something that is both.
Yes, that's right. 'Physical' in the SUMO means something like possible
individual. It covers any conceivable 'Process' or 'Object' and, thus,
covers things like Sherlock Holmes, the Starship Enterprise, the election of
Al Gore as President of the U.S. in 2000, and all other internally
consistent fictional things.
>
> Any such ontology needs to admit of two possibilities:
>
> * that we discover some thing that really is not either an A
> XOR a B - this would represent a falsification of the theory
> underlying the ontology that would be better addressed by
> reconstructing the highest level of the ontology than making
> ad hoc modifications to it (such as deciding that it is,
> after all, possible for something to be both a possible
> individual and an abstract object)
Well, I think what Pat has in mind (and he can correct me if I'm wrong) is a
different possibility. I think he's willing to admit that 'Physical' and
'Abstract' partition the conceptual space of 'Entity' (the root node of the
SUMO), but I think he also wants to embrace some classes that are a
combination of instances of 'Physical' and 'Abstract'. There are some such
structures already in the SUMO. For example, 'SelfConnectedObject' and
'Collection' form a partition of 'Object'. However, we have another class
called 'Region' directly under 'Object', because the notion of a region is a
useful one and some regions are self-connected (e.g. islands) and some are
not (e.g. archipelagos). If I understand Pat right, then, as I mentioned in
my previous message, I think the burden is on him to clearly define some
classes that mix 'Physical' and 'Abstract' and have obvious utility.
>
> * that the knowledge I have of something may be incomplete -
> I may at some point discover some thing X but not have
> determined (or have no way of determining) what kind of thing
> it is, even at the level of its classification (in EPISTLE
> terms) as a possible_individual or an abstract_object. The
> existence of a 'top' or 'thing' class (which you cite as
> being neither abstract or physical in the SUMO case, but I
> would interpret as being the union of both) would allow be to
> acknowledge the existence of X as a thing [1]. Therefore,
> 'Pat Cassidy' is a member of EPISTLE:possible_individual,
> 'ontologist' is a member of EPISTLE:abstract_object, and both
> are members of EPISTLE:thing (which is, in fact, the only
> class that both can be a member of within this particular ontology).
>
> I would also, by the way, be wary of using inheritance
> mechanisms as a means to construct an ontology - inheritance
> should be a consequence of the relationships defined in the ontology.
>
> regards
> Julian
>
> [1] The formal definition of the EPISTLE core model doesn't
> actually allow me to do this, but that's a consequence of
> itgs schitzophrenic existence as an ontology and as a data model.
>
> -----Original Message-----
> From: Patrick Cassidy [mailto:pcassidy@bellatlantic.net]
> Sent: 2003-06-27 12:51
> Cc: standard-upper-ontology@ieee.org
> Subject: SUO: Problems in SUMO
>
>
>
> After working on OpenCyc for a while, I will
> now inquire about some features of SUMO whose
> motivation isn't clear to me.
> Just one issue for this note. Is there
> a need for SUMO to have only two top classes,
> "Physical" and "Abstract"? Other ontologies have
> more than those two at the top semantic level.
> CYC for example, has "PathSystem" which has
> both physical and abstract subclasses. Wordnet
> has over a dozen top categories. I have over a dozen
> in the ontology I am building, such as "Object" which
> can have both abstract and physical subtypes.
> The point is that there are concepts that have
> both Abstract and Physical subclasses, so cannot be
> considered either Physical or "Abstract", where
> "Abstract" means inheritably abstract. In common
> usage, "abstract" merely means "not physical"
> but for classes, that should not necessarily
> entail that the "Abstract" quality is inheritable.
> If SUMO were willing to admit additional classes
> into the top level, it could be made more closely
> interoperable with other ontologies.
>
> One additional note:
> For those who might be tempted to object that
> surely all instances of things in the world can
> be classified as "abstract" or "physical", I agree.
> But that kind of binary classification to generate
> a hypercube space of all possible points in
> an abstract concept-space is a different sort of
> classification from the inheritance hierarchies that
> are far and away more typical for ontologies.
> The two methods of classification are incompatible
> if one wants to view the points in concept space
> as classes that are disjoint in any given dimension.
> Consider just the "Top" level. That itself is
> nether "Abstract" nor "Physical". So why not have
> other concepts that are neither?
>
> Pat
>
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