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Re: [ontolog-forum] Avoiding Hobson's Choice In Choosing An ntology

To: Chris Menzel <cmenzel@xxxxxxxx>, "[ontolog-forum]" <ontolog-forum@xxxxxxxxxxxxxxxx>
From: Patrick Durusau <patrick@xxxxxxxxxxx>
Date: Sun, 30 Apr 2006 09:08:27 -0400
Message-id: <4454B6CB.60401@xxxxxxxxxxx>
Chris,    (01)

Chris Menzel wrote:    (02)

>On Sat, Apr 29, 2006 at 11:19:55AM -0400, Patrick Durusau wrote:
>>...Finally, it is FOL that imposes limitations on mapping.
>>Assume that we have an experienced analyst that is reviewing
>>information that has been recorded in a subject map using subject
>>proxies. Due to their experience, they have reached a conclusion that
>>what appears to be two distinct individuals is actually one. A
>>conclusion that would result in merging proxies that represent the
>>purchaser of weaponized anthrax and a recent entry into the US.
>>They may not have an articulable basis for that conclusion and so FOL
>>is not going to be of any use. 
>I'm not at all sure what an "articulable basis for a conclusion" is, but
>why does one need such a basis any more in the case of an identity
>assertion than in any other case?  If the analyst comes to believe that
>S1 is in Afghanistan, she writes: In(Afghanistan,S1).  If she comes to
>believe that individuals S1 and S2 are one and the same, she writes: 
>S1 = S2.
Quite true, but as I noted yesterday, there is a difference between 
using FOL to represent the conclusions of the analyst and saying, "see 
the power of an FOL based system."    (03)

In most contexts, FOL is touted as a means to "reason" about information 
in a knowledgebase. In the example in dispute, FOL is simply 
representing the conclusion of a human analyst.    (04)

>>Should they simply not request merging the proxies on the basis of
>>their judgment (assume the analyst is also identified as a subject)
>>since they have no way to express it in FOL?  Hardly, one has a
>>merging rule that says Analyst X says proxy A and proxy B represent
>>the same subject. Utterly outside of FOL. 
>Not at all, though of course you need to use first-order theories that
>enable you to express information about the appropriate objects,
>properties, and relations.  In particular, your rule above is easily
>formalized in a first-order theory that contains appropriate operators
>and terms to represent beliefs and/or assertions.  There are numerous
>first-order frameworks in which this is possible.
Yes and as I note above, that is representation of the input of a human 
operator, not a conclusion reached by the use of FOL.    (05)

>>Apologies for the length to anyone who has gotten this far. I deeply
>>respect the power of FOL and think it should be used whenever
>>appropriate. But the key word in that statement is *appropriate.*
>Seems to me it is *always* appropriate when the point is representation;
>I mean, why tie your hands expressively if the point is to get the
>nature and structure of the relevant information right?  That said, of
>course, one might well use a weaker logic, or a non-classical logic, if,
>say tractable or defeasible reasoning is needed.
Let's separate out the use of FOL for representation and the use of FOL 
for reasoning, as you appear to do so in the last sentence of your post.    (06)

Even assuming that FOL is sufficient for any representation (a point you 
assume and I don't want to be diverted onto), why should any system 
exclude other means of representation?    (07)

In other words, why should a college dean, chemistry professor, 
physician, stock trader, economist, or even an elected official, ;-) , 
have to use FOL to represent their subjects in an information system? 
Granted it creates more work for the authors of FOL representations but 
I am assuming that is not the primary goal of building systems with FOL 
representations.    (08)

For those of you who have read the TMRM draft, it notes at the outset 
that any subject can have any number of descriptions. The goal of the 
TMRM was to specify the disclosure necessary to enable the merging of 
multiple descriptions of the same subject. Some of those descriptions 
may be based on FOL. Some may not be. But they are all legitimate 
descriptions of the same subject.    (09)

What do we gain by disenfranchising users who have non-FOL descriptions 
of their subjects? (serious question)    (010)

I have some ideas on what we lose by requiring only FOL descriptions:    (011)

1. The number of users who can usefully contribute information to a 
system is greatly reduced.    (012)

2. The variety of descriptions of subjects is reduced.    (013)

3. The systems in which such descriptions were developed are not 
represented or at least not independently of FOL.    (014)

In other words, if all descriptions must be translated or reduced to 
FOL, then we have lost the original descriptions of subjects by those 
most concerned with them, the users. So why use a lossy system when it 
is unnecessary?    (015)

Note that we are only talking about "description" using FOL. I don't 
think it is legitmate to say that if we have FOL descriptions then it 
follows that an FOL system can "reason" about those subjects. It 
certainly can, but then the question is whether the outcomes of that 
reasoning make any sense to the ultimate users.    (016)

Hope you are having a great day!    (017)

Patrick    (018)

>Chris Menzel
>Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
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>    (019)

Patrick Durusau
Chair, V1 - Text Processing: Office and Publishing Systems Interface
Co-Editor, ISO 13250, Topic Maps -- Reference Model
Member, Text Encoding Initiative Board of Directors, 2003-2005    (020)

Topic Maps: Human, not artificial, intelligence at work!     (021)

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