ontolog-forum
[Top] [All Lists]

Re: [ontolog-forum] Role of definitions (Remember the poor human)

To: Pat Hayes <phayes@xxxxxxx>
Cc: "[ontolog-forum]" <ontolog-forum@xxxxxxxxxxxxxxxx>
From: Duane Nickull <dnickull@xxxxxxxxx>
Date: Wed, 14 Feb 2007 15:40:59 -0800
Message-id: <C1F8DE0B.833F%dnickull@xxxxxxxxx>
Pat:    (01)

When I say context, I like to use the wordnet definition:    (02)

"discourse that surrounds a language unit and helps to determine its
interpretation"    (03)

Yes - a "river" is always a "river" hence its name.  A more accurate
depiction of what I meant to say is that a certain instance might be a
"river" in one context and not in another as you suggest.    (04)

See below:
> 
>>  A glass of water sitting on a
>> desk in front of you will not be elevated in your own tuple stores yet a
>> glass of water approaching your windshield at 60MPH will based on your
>> perception that it is a threat to your safety.  They are the same object but
>> in different contexts have different meaning.
> 
> Hmm, context as relative speed: I think that is
> the first time I have come across that particular
> usage.    (05)

(DUANE):  I suspect that the geo-spatial-temporal relationship is one
context modifier but there would be others.  Temperature or granularity
might be another.  For example - what is "solid"?  To you and I, a sidewalk
is solid.  To a neutrino, it is not.  Not to worry as I don't know of many
neutrinos who are actively writing ontologies for a human audience but it
does illustrate the importance of the context being somehow present in an
ontology.    (06)

I would presume that the example above is based on an intersection of
multiple contexts.  Thinking about how you think is one of the hardest
activities anyone can do (or so I think).    (07)

>> Even the basic examples that used to come with Protégé were flawed IMO.  The
>> wine example was screaming for the aspect of context to be included in the
>> ontology given the concept of "best wine" is contextually dependent upon
>> your definition and criteria for "best".
> 
> It is dependent on your concept of "best", yes.
> Put another way, it uses the term in a very
> under-determined way. Why do you say this is
> "contextual", though? What has this situation got
> to do with contexts, and in what sense of
> "context"?
(DUANE):  I think the way I interpreted it, it *could* be a contextual
argument but also might not.  Since it is not defined in the example, I
found the example next to useless.    (08)

What would have been more accurate is a declaration that "<person_instance>
asserts that <wine_instance> is the best wine".  To me, this more accurately
reflects the facts that just stating "<wine_instance> is the best wine".    (09)

I was aware of the work that had been done but had not realized there were
active projects.  I would like to look into those more.  I find the thinking
very interesting.    (010)

Duane    (011)

> 
>>  Does it mean that I think it is
>> the best?  Is the the author of the ontology?
> 
> Presumably the latter.
> 
>>  Has some universally accepted
>> criteria been applied and used to judge it?
> 
> No.
> 
>>  Without the definition of
>> "best", the example is largely confusing and meaningless IMO.
> 
> It does not mean very much, but it is not
> meaningLESS. It has whatever meaning can be
> gleaned from the axioms in the ontology. The same
> is true for all concept names in any ontology.
> 
>> There have been some work done around context.  Most of it has failed or
>> resulted in an open ended explosion of hypothesis.
> 
> Well, quite a lot of reasonably serious work has
> been done without utter failure, though of course
> not entirely without controversy. There has been
> a series of quite technical workshops, for example
> 
> http://sra.itc.it/events/crr05/,
> http://www.nexus.uni-stuttgart.de/COMOREA/2006/CallForPapers06_files/comorea06
> -cfp.pdf
> 
> and some surveys and overviews are available
> 
> http://www-poleia.lip6.fr/~brezil/Pages2/Publications/CAI1-99.pdf
> (now rather old)
> http://www.cs.bilkent.edu.tr/~akman/book-chapters/mcgraw/mcgraw2002.doc
> 
> and I belive there is a journal devoted to the
> topic. John McCarthy was the first to suggest a
> contextual logic, and it has since been quite
> sharply formalized by others and has given rise
> to a lot of work, including many applications and
> implementations of context-reasoning engines (Try
> googling "context logic"). Cyc, probably the
> largest integrated ontology ever built, has been
> based firmly on context logic for a decade or so,
> and uses it centrally (their preferred term is
> 'microtheory' rather than 'context')
> 
>> It is my hope that one day a serious effort will start to really open this
>> topic up.
> 
> Im not sure what you regard as serious, but you
> might cast an eye over some of the literature. By
> the way, our logic IKL was developed in order to
> provide for a way of handling contexts in full
> generality but which does not require using a
> context *logic*. I can expand on this point if
> you are interested.
> 
> Pat
> 
> 
>> Duane
>> 
>> 
>> 
>> 
>> On 2/14/07 9:41 AM, "John F. Sowa" <sowa@xxxxxxxxxxx> wrote:
>> 
>>>  Pat, Chris, Kathy, and Barry,
>>> 
>>>  The problem of stating necessary and sufficient conditions
>>>  for defining anything is nontrivial, even in mathematics.
>>>  For phenomena in nature or the results of typical human
>>>  behavior, definitive statements are problematical, to say
>>>  the least.
>>> 
>>>  Belief revision systems, database systems, and knowledge-based
>>>  systems distinguish levels of "entrenchment" (whether or not
>>>  they use that term), and I believe that an ontology should also
>>>  make such distinctions at the metalevel.  Following are some
>>>  "levels of entrenchment" in descending order of strength:
>>> 
>>>    1. Type hierarchy.  The classical tree or partial ordering
>>>       introduced by Aristotle and first drawn by (or attributed
>>>       to) Porphyry.  It's useful in every field, it's not going
>>>       away, and we should recognize it as the minimal requirement
>>>       for an ontology.
>>> 
>>>    2. Necessary distinctions.  The differentiae that split any
>>>       type into two or more subtypes.  If the split is binary
>>>       (A or not-A), then it is both necessary and sufficient for
>>>       distinguishing the two subtypes from one another, but the
>>>       conditions for characterizing the supertype might not be
>>>       necessary and sufficient.
>>> 
>>>    3. Constraints.  Additional statements that characterize the
>>>       types or the interactions of entities of various types.
>>>       The constraints are necessary relative to the ordinary
>>>       facts in level #4, but they might not be considered
>>>       defining characteristics.
>>> 
>>>    4. Ordinary facts.  Ground-level assertions that must be
>>>       consistent with statements at the above levels, but they
>>>       may violate defaults at level 5.
>>> 
>>>    5. Defaults and probabilities.  Statements that are usually
>>>       true of entities of a given type or types, but they are
>>>       at the bottom of the entrenchment pole.  A probable
>>>       statement is a default with an associated value that
>>>       indicates its likelihood or frequency of occurrence,
>>>       given the occurrence of some other condition.
>>> 
>>>  Systems of entrenchment levels along such lines are widely
>>>  used and should be supported.  Cyc, for example, has 3 levels:
>>>  True, true by default, unknown (and the negations -- false
>>>  by default and false).  But I think that Lenat would agree
>>>  that a privileged level should be added for some of the
>>>  axioms, especially ones that define the type hierarchy.
>>> 
>>>  A declaration of which level a particular statement belongs to
>>>  would not be part of the first-order theory, but it would be
>>>  a metalevel statement that should definitely be considered
>>>  part of the ontology.
>>> 
>>>  John
>>>  
>>>  _________________________________________________________________
>>>  Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
>>>  Subscribe/Config: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/
>>>  Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
>>>  Shared Files: http://ontolog.cim3.net/file/
>>>  Community Wiki: http://ontolog.cim3.net/wiki/
>>>  To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx
>>>  
>> 
>> --
>> **********************************************************
>> Sr. Technical Evangelist - Adobe Systems, Inc.           *
>> Chair - OASIS SOA Reference Model Technical Committee    *
>> Blog: http://technoracle.blogspot.com                    *
>> Music: http://www.mix2r.com/audio/by/artist/duane_nickull*
>> **********************************************************
>> 
>> 
>> _________________________________________________________________
>> Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/ 
>> Subscribe/Config: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/ 
>> Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
>> Shared Files: http://ontolog.cim3.net/file/
>> Community Wiki: http://ontolog.cim3.net/wiki/
>> To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx
>> 
> 
> 
> --
> ---------------------------------------------------------------------
> IHMC  (850)434 8903 or (650)494 3973   home
> 40 South Alcaniz St. (850)202 4416   office
> Pensacola   (850)202 4440   fax
> FL 32502   (850)291 0667    cell
> phayesAT-SIGNihmc.us       http://www.ihmc.us/users/phayes
>     (012)

-- 
**********************************************************
Sr. Technical Evangelist - Adobe Systems, Inc.           *
Chair - OASIS SOA Reference Model Technical Committee    *
Blog: http://technoracle.blogspot.com                    *
Music: http://www.mix2r.com/audio/by/artist/duane_nickull*
**********************************************************    (013)


_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/  
Subscribe/Config: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/  
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/ 
To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx    (014)

<Prev in Thread] Current Thread [Next in Thread>