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Re: [ontolog-forum] Upper ontology content and structure

To: "'[ontolog-forum] '" <ontolog-forum@xxxxxxxxxxxxxxxx>
From: "Patrick Cassidy" <pat@xxxxxxxxx>
Date: Fri, 26 Sep 2008 15:14:33 -0400
Message-id: <011e01c9200c$1c031430$54093c90$@com>
Azamat,
   Regarding WordNet and ontologies:
> There is a popular benchmark, the WordNet hierarchy of things, setting
> the standard of quality. However inconsistent, it gives rather clear
> divisions: Entity (Physical Entity, thing, object, cause, substance,
physical
> process; Abstract Entity, psychological feature, attribute, group,
relation,
> communication, quantity, set, otherworld). How the COSMO ontology
> differs from it in a progressive way? Thanks.
>
  WordNet is used a lot in Natural Language Processing, but I have not heard
others say that it 'sets the standard of quality' for an ontology.  In fact,
there is almost universal agreement among those I know who have looked at it
for reasoning purposes that the top levels of WordNet do **not** constitute
a valid inheritance hierarchy that would be useful for automated
inferencing.  It was originally built as a psycholinguistic model of word
usage, and was not originally intended for automated inferencing or for NLP,
though being the only free semantic network of that size it was pressed into
use for that purpose, in spite of wide recognition of its defects.    (01)

  Nevertheless, in the current phase of the COSMO work (representing words
in the Longman defining vocabulary), I am adding pointers to WordNet synsets
for the elements (types and relations) being added.  The WordNet has over
100,000 synsets, so when a mapping of WordNet to a foundation ontology is
complete, there will still be many WordNet synsets not directly represented.
I have not yet attempted to examine the more specialized synsets of WordNet,
but I hope that they will more accurately reflect an inheritance hierarchy,
and if so, then the task will be to find the most specific subsumer for each
root of a WordNet subtree that is not represented in COSMO.  That is a task
that will not be done for over a year.   If it works as hoped, then we would
have a "modified" WordNet that would function as the linguistic mapping for
a true inheritance hierarchy.    (02)

Whether that reorganized WordNet will prove more useful than the original
will only be known when there have been serious attempts to compare them for
the same applications.  That may take a while, because most of the NL work
does not attempt to represent texts with the detail of meaning that is
encoded in a good logic-based ontology.   It will take time, even for NL
researchers who are so inclined (very much the minority at present), to
figure out how to use such a resource effectively.    (03)

But another issue should not be ignored.  The foundation ontology and
application-oriented specialized ontologies are very different things, with
different purposes, and at least some criteria for evaluation of one type
will not be appropriate for the other type.  The most critical function for
a foundation ontology, in my view, is to serve the purpose of enabling
accurate semantic interoperability by creating accurate maps from
application ontologies to  the foundation ontology, and via the foundation
ontology, mappings from application ontologies (or database schemas) to each
other.  Such mappings will be much less expensive if the specialized
ontology or DB schema is created by use of (i.e. the terms specified as
combination of) the basic concept representations in the foundation
ontology, rather than doing it as an afterthought.    (04)

In order to make its use as easy as possible, I am organizing the COSMO to
be at least a representation of the concepts in the Longman defining
vocabulary, which has been used to define specialized terms in dictionaries.
My working hypothesis (as I have mentioned before) is that a comparable
inventory of corresponding logical representations of those words will
function as a "conceptual defining vocabulary" - a collection of basic
concept representations that will be adequate building blocks to create
logical specifications of any specialized concept (or "thing", if one
doesn't believe in representing concepts) one wants to represent for an
application.  Aiming for the defining vocabulary is a means of keeping the
foundation ontology as small as possible, thereby making it as easy to use
as possible.
Whether such a foundation ontology will have such capability is an issue of
fact that can be resolved by experiment, not by discussion.  My current
agenda is: (1) supplement the COSMO to include representations of all words
in the Longman defining vocabulary (and some others that appear equally
basic); and (2) try to use that ontology to represent many different
specialized concepts, to determine whether the initial inventory needs to be
supplemented with additional primitive concept representations, and if so,
by how many.    (05)

The question of how many "primitives" are needed to create the more complex
concepts in common use is one that has been discussed for some time.   I
believe that the use of a foundation ontology as an inventory of such
primitives is a valid method for actually investigating this issue in an
objective experimental manner.    (06)

Pat    (07)


Patrick Cassidy
MICRA, Inc.
908-561-3416
cell: 908-565-4053
cassidy@xxxxxxxxx    (08)


> -----Original Message-----
> From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx [mailto:ontolog-forum-
> bounces@xxxxxxxxxxxxxxxx] On Behalf Of Azamat
> Sent: Friday, September 26, 2008 1:01 PM
> To: [ontolog-forum]
> Subject: Re: [ontolog-forum] Upper ontology content and structure
> 
> On Friday, September 26, 2008 3:05 PM Patrick Cassidy wrote:
> 
> ''However, if anyone were interested in trying to figure out which of
> those
> categories applies to the elements of the COSMO ontology:
> http://www.micra.com/COSMO/
> I would have no objection.  If some useful function could be
> demonstrated by
> the act of such a classification, I would be intrigued and may change
> my
> mind about their usefulness.''
> 
> I propose to review the extant upper ontologies, COSMO, SUMO, BFO,
> DOLCE,
> etc. including the OWL sequels, according the following criteria:
> 1. how comprehensive their class (or type) and relationship
> hierarchies;
> 2. how consistent their categorical structures to represent the world;
> 3. how expressive their languages to understand the world, its parts
> and
> domains;
> 4. how effective their  key meanings, concepts, definitions,
> principles,
> axioms, rules to apply for practical domains;
> 5. how efficient these top ontologies for building ontology technology,
> reasoning applications and semantic systems and knowledge technologies,
> as
> SW or Future Internet.
> 
> Re COSMO. While trying to find out the number one point, i read in the
> Overview:
> '' Most of the types (OWL classes) in the current COSMO have been taken
> from
> the OpenCyc OWL version 0.78, and from the SUMO.  Other elements were
> taken
> from other ontologies (such as BFO and DOLCE) or developed specifically
> for
> COSMO.  As of version 0.52 (July 2008) the COSMO had 5280 classes
> (types)
> and 556 relations.''
> 
> As far as the project is proposed as a foundation ontology, it would be
> engaging to see its top hierarchy of entities and relations, its
> similarity
> or difference from cogent systems.
> 
> There is a popular benchmark, the WordNet hierarchy of things, setting
> the
> standard of quality. However inconsistent, it gives rather clear
> divisions:
> Entity (Physical Entity, thing, object, cause, substance, physical
> process;
> Abstract Entity, psychological feature, attribute, group, relation,
> communication, quantity, set, otherworld). How the COSMO ontology
> differs
> from it in a progressive way? Thanks.
> 
> 
> 
> Azamat Abdoullaev
> 
> 
> 
> 
> 
> 
> -
> ---- Original Message -----
> From: "Patrick Cassidy" <pat@xxxxxxxxx>
> To: "'[ontolog-forum] '" <ontolog-forum@xxxxxxxxxxxxxxxx>
> Sent: Friday, September 26, 2008 3:05 PM
> Subject: Re: [ontolog-forum] Upper ontology content and structure
> 
> 
> Mike -
>   Concerning your question:
> 
> >
> > MB> It also made sense to me, to distinguish between first- second-
> > > and third-order classes of Thing, as defined by John Sowa and
> > > others (John's book summarises the history of those terms very
> well).
> >
> > MB> What interests me, and what I am really asking here, is why is
> > > this approach not noticeable in upper ontology resources like
> > > the Suggest Upper Merged Ontology (SUMO)? Am I missing something?
> > > SUMO looked to me like a single taxonomic hierarchy of classes
> > > of Thing, without these three sets of partitions.
> >
> 
>    I can't answer for SUMO, but I can tell you why those distinctions
> don't
> appear in COSMO:
>    *** there is no apparent need for them, and spending time trying to
> decide into which of those abstract categories one might place specific
> types or relations does not make any sense to me, as they add nothing
> to the
> intended meaning. ***
>     Wherever one might think that a type or relation fits one of those
> categories, the more specific and meaningful type or relation itself
> will
> carry all the meaning required to perform the intended function of the
> ontology.
>     The top level of COSMO under 'Thing' has 20 types, and one of the
> those
> ('Individual') is a heterogeneous grouping of other types that are
> mostly
> heterogeneous groupings associated by some property (a 'faceted'
> categorization).  If I had 'firstness' secondness' and 'thirdness' at
> the
> top level, I expect that few people wanting to find some particular
> type of
> thing would have no idea where to start in the drill-down process.
> Tools
> like Protégé that allow searching for substrings in the label for a
> type
> help immensely, but as far as creating a hierarchy for drill-down when
> string search fails, those three abstract categories, in my estimation,
> are
> quite useless.  I am very concerned with usability of any ontology,
> meaning
> that it has to be as easy as possible to understand, while preserving
> its
> technical adequacy.
> 
>    Those abstract categories may be interesting for philosophical
> speculation, but I have never observed any function for them in
> automated
> reasoning.  More specific issues dominate my concerns about
> representing
> meaning.
> 
>    If they help you organize your own thinking about the meanings of
> concepts, they may be useful, for you, for that purpose.  I haven't
> found
> them useful in that way.
> 
>    However, if anyone were interested in trying to figure out which of
> those
> categories applies to the elements of the COSMO ontology:
> http://www.micra.com/COSMO/
> I would have no objection.  If some useful function could be
> demonstrated by
> the act of such a classification, I would be intrigued and may change
> my
> mind about their usefulness.
> 
> Pat
> 
> Patrick Cassidy
> MICRA, Inc.
> 908-561-3416
> cell: 908-565-4053
> cassidy@xxxxxxxxx
> 
> 
> 
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