[topicmapmail] Subject Identifiers metadata

[Kal Ahmed]

On Sat, 2004-05-01 at 01:24, Thomas B. Passin wrote:
> Kal Ahmed wrote:
> 
> > 
> > The note says that you cannot reify a topic. You can, however reify any
> > characteristic of the topic. Can you give an example of the need to
> > reify the topic ? For example it is not really meaningful IMHO to say
> > "topic X was created by user Y", whereas I think it is meaningful to say
> > that "the assignment of name A and occurrence B to topic X was done by
> > user Y".
> > 
> 
> To reify a topic must mean that you want to talk about it as a concept. 
>   Otherwise you would be talking about its subject, and the topic 
> already exists for that.  So one means to talk about a particular data 
> structure inside a computer.  I think it is perfectly fine to use the id 
> of a topic for that purpose, and, as Steve Pepper said, all you need is 
> the right PSI.  Add an occurrence to hold the id value and you have what 
> you want.
> 
> But maybe the original assignment was to talk about the identifier 
> itself - for example,
> 
> "The topic identifier "t-boston-red-sox" was computed by the engine from 
> the baseNameString "Boston Red Sox" assigned by the user."
> 
> Still no problem.  We create a new topic type for this notion, 
> preferably describing it with an appropriate PSI, and again just use an 
> occurrence to hold the actual value.
> 
> Kal also said -
> 
> "For example it is not really meaningful IMHO to say
> "topic X was created by user Y"
> 
> I don't know why not.  The topic may *in fact* have been created by user 
> Y on April 24, 2004 in Boston, MA, USA, and a system may want to keep an 
> audit trail of information like that.  Many large systems do.  Remember 
> that the topic is something distinct from its subject, although a given 
> concept may be said to have been created by someone at some time (but 
> let's not get into that philosphical black hole!)
> 
I'm not talking about reifying a <topic> element or reifying some
construct in a topic map processing engine. I'm talking about reifying a
topic construct. In the "binding point" model of topic maps, the topic
is essentially nothing but a place to hang assertions - in other words
it comes into being by a user making an assertion about a subject. So it
is the assertion that is created by the user, the topic being a
side-effect.

Cheers,

Kal
-- 
Kal Ahmed <kal@techquila.com>
techquila