[sc34wg3] TM Data Model issue: prop-subj-address-values

Murray Altheim sc34wg3@isotopicmaps.org
Mon, 03 Nov 2003 14:47:10 +0000

Graham Moore wrote:
> Kal wrote:
>>>FACT: 1 topic can only represent one subject
> No, 1 topic *should* represent one subject but as we know the SLUO is not
> achievable.
>>>FACT: 1 resource is one subject 
> Indeed but that doesn't matter.
> Both subject identifiers and subject addresses are means of establishing
> identity. There is no guarentee of correctly determining (when the URIs are
> different) whether they are representing the same subject. So I think the
> comparison is a useful one and gives good guidance as how we should proceed.

[pardon me if I wax philosophic here...]

As I've been harping on about for months on some of the ontology-
related lists, a lot of the issues of identity should be considered
as triadic rather than diadic relations. Basically, wherever humans
put meaning on something (which is the case when establishing identity),
we are dealing with an issue of interpretation. [By the word "interpret",
I mean "to give or provide meaning for", a human process that is *always*
within a specific context (i.e., I'm not talking about any kind of
"machine interpretation" here)].

In this sense, "FACT" #1 is not achievable simply because we're dealing
with an issue of interpretation. As the context changes, so does the
meaning. That's why the SLUO is not achievable. People who think otherwise
are ignoring the idea that the publishing of a Topic Map is simply another
form of communication, just like the publishing of a dictionary. It's
people's misunderstanding of the purpose of a dictionary that leads to

"FACT" #2 is also dependent upon context to a great degree, since
the definition of "resource" is not fixed. Does "resource" refer to
the document-as-object, the bytes received via a download, the
idea of the resource *as* a resource (absent any further meaning),
the idea of it as a web page, as a "home page", etc.

One of the things it's been difficult to get my head around, and
difficult to explain to others, is the idea that attempts to declare
meaning are rather misguided so long as one believes there is some
canonical, Platonic concept behind that declaration. We're all in
the process of trying to *communicate* concepts -- just as a
dictionary only describes or communicates common practice in the
usage of words (people often erroneously think of dictionaries as
an authority on the language. On the contrary, nobody controls or
owns a language, despite the attempts of despotic governments
throughout history).

The statements (or "ontological commitments") made in a Topic Map
are always an act of communication between its author and an
"intended audience". There's a bit of an illusion that a Topic Map
can be truly universal, that the document can be reliably reused
under all contexts or circumstances. It's up to the author to
provide information to assist users of the document to understand
how the communication was intended -- just as in any communication,
a misunderstanding in this regard is very likely to lead to
miscommunication. I like the idea of PSIs, but inherently understand
that it's simply a form of communicating what an author intends as
a set of subjects. There is still ambiguity in that.

We try to describe things during our communication with others.
Publishing a Topic Map is essentially saying, "this is what I
mean by 'X'". What we're trying to do here is remove as much of
the possibility of ambiguity as possible, but as in *any* form of
communication, it's tacitly impossible to be completely unambiguous;
we do the best we can.

In ontology, statements are considered "ontological commitments",
not "facts". Not everyone believes in the existence of "facts", or
at least doesn't assign them any more epistemological weight than
"well-regarded opinions". (e.g., is it a fact or not that light
cannot travel faster than 186,000 miles per second? Some might
assign this "fact" status, but physicists aren't really sure, just
"reasonably sure", and some disagree. Reason involves
interpretation. It's best to consider even the speed of light as
a ontological commitment, and go from there.)

I'm not sure if any of this is helpful to the discussion, but you
guys all know me well enough by now to know I just can't keep my
mouth shut on some issues... :-)


Murray Altheim                    http://kmi.open.ac.uk/people/murray/
Knowledge Media Institute
The Open University, Milton Keynes, Bucks, MK7 6AA, UK               .

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