[topicmapmail] Getty Art and Architecture Thesaurus On Line

[Murray Altheim]

Thomas B. Passin wrote:
> [Murray Altheim]
[...]
>>Except that to my understanding of RDF/OWL, what you've written, is that
>>the statements are incorrect. "domain" is not a subclass of "Class", nor
>>is "range" is not a subclass of "Class".
> 
> In OWL, "subclassOf" is an (RDF-style)  property.  It may be applied to
> resources of type "Class" (its domain) and it may have values of type
> "Class" (that is its range).

This is where the modeling breaks down. It *should* only be applied to
things of type "Class" within a given context.

>>Neither is "Homo sapiens" a
>>subclass of a species, rather an instance of a species. Perhaps I'm not
>>understanding what you're saying correctly, as this seems fairly straight-
>>forwardly wrong. Could you clarify?
> 
> I assumed that when you said "species", you meant a categorizing term, and
> so I am calling "species" a Class.  If this is correct, then "Home sapiens"
> is precisely a subclassOf "species", isn't it?  If not, we are getting into
> terminology, and I really meant to show how it is possible to distinguish
> between different uses of what you are calling "instance", by means of
> specifying the allowed domains and ranges.  IOW, I think you are using the
> word "instance" to mean different things in the two cases, and I think that
> some other term should be used to distinguish the two.

No, I don't think the terminology is incorrect, it's just that things can
be instances or not within specific contexts. "species" is a class in one
context (when it is used as a categorizing term) and is an "instance" in
the context of being an instance of a zoological taxonomical category (or
taxon, for short).

> What is this distinction that I am claiming?  In the one case you expect the
> target of "instance" to be a class (or species, or whatever collective term
> you want to use), in the other you expect it to be an individual thing, like
> an antelope or rose - that is, an individual as opposed to a collective
> concept.

Yes, this is what I'm claiming.

> If topic maps had a defined vocabulary that included something like domain
> and range, you could precisely make clear what you have in mind here.  And
> if you truly want to include both senses of the term "instance", with OWL
> you could do it by specifying (possibly anonymous) union classes to get both
> ranges combined.

Well, just as RDF on its own cannot model much of anything, (it's just
a graph syntax), it took OWL to provide it with a modeling language,
specifically itself an instance of a Description Logics language (in
various forms). That makes it suitable for people who agree with the
logic of DL, unsuitable for those who don't. There are a lot of competing
schools of thought on this one; the DL folks happen to have the DARPA
money and TimBL's ear. Bully for them. Not interesting to me.

>>>My point here is that I think of these two usages of "instance" as
>>>different relationships, since they have different ranges.  [...]
>>
>>Actually, better definitions can be found in either Cyc, SUO, or the
>>recently-announced ISO 15926 definitions. See
>>
>>Now, there are many ways to skin a cat. I'm not particularly fond of this
>>scheme, but it apparently works for the audience of ISO 15926.
>
> I see why you say that ... I just looked at the entry for "Class" and I
> think it is pretty weak.

Point is, each to their own. It apparently works for their needs and
agrees with their philosophy.

>>The problem is not that there isn't an available definition of a class-
>>instance relationship, it's that there are a number of competing ones,
>>such as classes built upon their membership (extensive) or by their
>>characteristics (intensive).
>
> As I said, I'm not looking to get into terminology (and definitions of
> "class" and "instance") here - well, I guess it can't be entirely avoided,
> can it?  My claim, I think, is that if we could define the domain and range
> (or some equivalents), it would be much easier to say whether in fact your
> "instances" do or do not mean the same thing.

I don't think you can avoid ontological commitment. I'm only advocating
that we don't create *one* for topic maps and force it down everyone
else's throat the way the DARPA/OWL/RDF community has for themselves.
(I suppose if you're in the RDF community and you don't agree with DL
you can do something else, but you'd probably be branded a heretic.)

>>>Maybe we should define what a class is, for the purposes of being more
>>>precise about themeaning of superclass-subclass and instanceOf.
>>
>>I think a more appropriate thing than *us* doing it, is to simply use
>>PSIs pointing to the various existing definitions as developed within
>>each of the various competing schools of thought on the subject.
>
> Yes, I would think so.
> 
>>... As I said, I tend to agree with Peirce and think that
>>knowledge representation only has validity as a form of communication
>>of non-Platonic concepts within a specific, given interpretation. You
>>need thirdness, context.
>
> I really only know about Pierce's writings from reading Sowa so far, and I
> am not that clear about thirdness.  I don't automatically equate thirdness
> with context, but I can see that context might act in that capacity.  I need
> to think about it some more.  Any suggestions for non-Sowa writings about
> Pierce that help to penetrate the terminology (with an eventual aim of being
> able to grasp the man's writings themselves)?

While I certainly think Sowa has a good handle on Peirce, I don't think
he's necessarily a Peircean. So he *might* not be a good source. I'm not
in a position to judge.

As for sources on Peirce, Mary Keeler has a few writings, but probably
the best is to simply read him. There are a number of published texts.
But for myself, I'm currently reading Robert Brandom and finding his
ideas very compelling. I'm not yet able to distill what I'm learning,
but I'd recommend his "Articulating Reasons: An Introduction to
Inferentialism". Noting that if I remember correctly, publicly Sowa has
derided Brandom only makes me more curious. Jon Awbrey has a pertinent
message on this subject [3], as well as Frithjof Dau and Julia Klinger [4].

>>I don't believe you can create static, universal class definitions. John
>>Sowa has stated [1][2] that he thinks that through careful analysis the
>>human community could eventually "discover" these Platonic ideals.
>
> When I read Sowa's post, I did not take it that way.  He talks about
> arriving at some satisfactory upper ontology by empirical means, and I think
> of that as being quite distinct from discovering Platonic ideals.

This is why I don't think John is necessarily a Peircean. On the one
hand he makes statements about Cyc microtheories and things that would
lead me to believe we agree, on the other he *does* state that via
"empirical" analysis we can come to universals. Well, that's pretty
much a definition of Platonic as far as I understand it, i.e., that
we're not there yet, but that they exist, and if we use some sort of
correct scientific process we'll get there. I don't think we can get
there because I don't believe universals exist. Full stop. So rather
than try, you create statements, communiques written by humans, within
a given context. This is pretty much the movement within philosophy
within the past fifty years, from Wittgenstein to Rorty to Brandom:
that representation is a form of contextualized communication, not
a statement of some ideal.

Murray

[1] http://www.infoloom.com/pipermail/topicmapmail/2003q2/004805.html
[2] http://suo.ieee.org/email/msg09656.html
[3] SUO: Re: On To Ontological Relativity, Jon Awbrey.
     http://grouper.ieee.org/groups/suo/email/msg10535.html
[4] From Formal Concept Analysis to Contextual Logic, F. Dau & J. Klinger
     http://www.mathematik.tu-darmstadt.de/~jklinger/ICFCA2003.pdf
...........................................................................
Murray Altheim                         http://kmi.open.ac.uk/people/murray/
Knowledge Media Institute
The Open University, Milton Keynes, Bucks, MK7 6AA, UK                    .

   The Office of Special Plans (OSP) was set up by the defence secretary,
   Donald Rumsfeld, to second-guess CIA information and operated under
   the patronage of hardline conservatives in the top rungs of the admini-
   stration, the Pentagon and at the White House, including Vice-President
   Dick Cheney. The ideologically driven network functioned like a shadow
   government, much of it off the official payroll and beyond congressional
   oversight. [...It] also forged close ties to a parallel, ad hoc intelli-
   gence operation inside Ariel Sharon's office in Israel specifically to
   bypass Mossad and provide the Bush administration with more alarmist
   reports on Saddam's Iraq than Mossad was prepared to authorise.
   http://www.guardian.co.uk/Iraq/Story/0,2763,999737,00.html

   (my longest .sig!)