[sc34wg3] What do we mean by reification?

[Steve Pepper]

At 14:03 03.03.2003 -0500, Patrick Durusau wrote:
>Where I am lost here is the **The basic topic map model does not allow 
>this** portion. If a subject is anything whatsoever I want to talk about, 
>why are association occurrences and giving an occurrence a name excluded 
>from that ambit? (Is this a question of XTM syntax? That may be where you 
>are losing me.)

Patrick,

In the topic map standard, occurrences cannot have names, associations 
cannot have occurrences, names cannot play roles in associations, etc. Right?

The only way you can make an assertion about anything in topic maps is by 
creating a topic for it - and then assigning characteristics to that topic.

That's all Lars Marius is saying. It's Topic Maps 101, isn't it?

So if you want to say something more about, say, the relationship 
represented by an association, you have to create a topic for it.

There is a technique - fairly well documented since XTM 1.0 - of using the 
source locator of a topic map object (e.g. an <association> element) as the 
value of a <subjectIndictorRef> in a <subjectIdentity> element. This is, in 
effect, saying that the subject of the topic in question is the 
relationship represented by the <assocation> element. SAM wants to call 
*this* process "reification" and distinguish it from the general, 
run-of-the-mill act of creating a topic.

I think that makes sense. There is a need for a special term that 
distinguishes these two cases and the SAM's usage *does* seem to accord 
with general practice in AI.

Steve

--
Steve Pepper, Chief Executive Officer <pepper@ontopia.net>
Convenor, ISO/IEC JTC1/SC34/WG3  Editor, XTM (XML Topic Maps)
Ontopia AS, Waldemar Thranes gt. 98, N-0175 Oslo, Norway.
http://www.ontopia.net/ phone: +47-23233080 GSM: +47-90827246