[sc34wg3] 5.4.3 Topic Characteristics

Lars Marius Garshol sc34wg3@isotopicmaps.org
17 Nov 2003 11:55:04 +0100

* Patrick Durusau
| With reference to 5.4.6 Properties, topic items have the following
| properties:
| Topic characteristic:
| 1. [topic name]
| 2. [occurrences]
| 3. [roles played}
| Non-Topic characteristic:
| 4. [subject identifiers]
| 5. [subject locator]
| 6. [reified]
| 7. [source locators]
| 8. [parent]
| Is this correct?

Absolutely correct.
| What is the basis for [subject identifiers] and [subject locators]
| not being statements about the subject, assuming I have the
| distinction correct?

I guess another way to explain this is to talk about the Subject
World. That's where the subjects are, and that's where we live. The
purpose of the topic map is to provide a map of the Subject World.
If I say

  [patrick : person]

I am making a statement about Patrick's position in the Subject World
(he's an instance of the type person).

If I say

  [patrick @"http://psi.ontopia.net/topicmaps/people/#patrick-durusau"]

on the other hand, I am not making a statement about the Subject
World; I am making a statement about the topic "patrick" (the *topic*,
the symbol that represents the subject Patrick) and its correspondence
with a subject in the Subject World.

Looking at the second TM fragment one really learns nothing about the
subject (unless, of course, you actually read the subject indicator,
but that's not part of the topic map; only the URI is). Looking at the
first you do learn about the subject.

Do you see the difference? 
| I may be missing a perfectly obvious reason for the distinction (or
| have the distinction wrong altogether!) hence the questions.

No problem. This is a good question.

Lars Marius Garshol, Ontopian         <URL: http://www.ontopia.net >
GSM: +47 98 21 55 50                  <URL: http://www.garshol.priv.no >