[topicmapmail] Are Facets Really Simple After All?

[Murray Altheim]

Kal Ahmed wrote:
[...]
> The discussion itself is useful if it is to help us distinguish
> different types of "information relevant to a subject" and I encourage
> that - indeed I have found this whole thread a very interesting one. My
> only point is that you seemed to me to be implying that ISO 13250
> constrains the use of occurrences in a way which from reading the
> definitions I feel it clearly does not.

I'm sure we've both read over the standard enough times between us
to make it a bestseller. In my reply today to Thomas (at 6:32pm),
I tried to make it clear that simply I am *very* uncomfortable
with what I consider a misuse of the term "occurrence" -- not that
the standard states clearly what constraints may be put on what is
or what isn't a Topic occurrence. It of course makes clear not to
put any constraints at all, but that doesn't mean there aren't
inherent, semantic constraints within a specific application. I
think it would have been severely limiting to create any explicit
constraint within the standard, as the applications of Topic Maps
may be *very* wide, and this kind of thing is quite application
dependent.

But by the same token, I think simply a pragmatic analysis of
what you're proposing should suggest some best practices. By that
I mean, a simple reading in English of what you're suggesting.
I can understand that an occurrence of the Topic "Paris, France"
might be a latitude/longitude for Paris, an important date in
its history, a photograph of the Champs Elysees, etc. The standard
rightfully doesn't constrain any of this kind of thing; it would
make Topic Maps much less interesting and valuable. But I can't
imagine that a "correct" occurrence of the Paris Topic would be
"2003-11-23T11:34:55", "245,190", or "#bce033" (i.e., the creation
date of the Topic in my application, the location of the Topic
node in my TouchGraph visualization, or the colour of the displayed
node, resp.). That just isn't right. Now, if I never planned to
share that Topic Map with anyone, hell, I can do what I like*),
but it doesn't *to me* express a correct interpretation of the
standard. Even in the inimitable vagueness of its definition of
"occurrence", a property of a Topic and an occurrence of a
Topic simply aren't the same thing. Certainly not semantically.

Murray

* as Alan Ginsburg says, "If we don't show anyone, we're free
   to write anything."
......................................................................
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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