[sc34wg3] 5.4.3 Topic Characteristics

Patrick Durusau sc34wg3@isotopicmaps.org
Mon, 17 Nov 2003 10:07:42 -0500


Lars Marius Garshol wrote:
> * Patrick Durusau
> | 
> | 

> | 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? 
Yes, I think I see the difference you are trying to illustrate, but let 
me say it a little differently:

[patrick : person]

I read that as a statement about the topic "patrick", that is the symbol 
that represents the subject Patrick. The subject Patrick can only be 
represented in the topic map by use of a proxy, that is a topic.

In other words, all statements in a topic map are about topics, some of 
which are proxies for subjects in the Subject World (conceding your 
distinction for purposes of this argument only).

Not meaning to get bogged down in the endless metaphysics that have 
bedeviled us in the past. I see a difference in how topic 
characteristics are handled in the TMDM from non-topic characteristics. 
It may very well be the case that for clarity, efficency, processing 
requirements, etc., that the distinction is necessary but we need to 
have a good reason for the distinction.

It may be the case, for example, that we think the current topic 
characteristics are enough for distinguishing the subject of one topic 
from another. That is certainly a position with which one could agree or 
disagree, all without worrying about the Subject world or the TM one 
(assuming one thinks they are separate).

The data model (any data model) has to stop eventually and say these are 
the things that are inside the data model and everything else is 
outside. A data model for today is not a suicide pact to avoid all 
future change so let's not look for deep reasons to justify what are 
choices to serve our needs of today. There are any number of places 
where I would probably draw some lines differently but that is what the 
five year review process in ISO is all about. Some things that we think 
are "must have" for today may be irrelevant in five years while things 
we don't even imagine may be pressing issues. I for one don't want 13250 
to ossify as have some ISO standards. (Sorry, getting ready for the SBL 
annual meeting later this week and that always makes me a little preachy.)

Hope you are having a great day!


> | 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.

Patrick Durusau
Director of Research and Development
Society of Biblical Literature
Chair, V1 - Text Processing: Office and Publishing Systems Interface
Co-Editor, ISO 13250, Topic Maps -- Reference Model

Topic Maps: Human, not artificial, intelligence at work!