[topicmapmail] Subject Identifiers metadata

[Thomas B. Passin]

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!)

Jan said -

"Or do you suggest simply putting in the prose of some subject indicator
"The topic that has the URI of this resource as a subject identifier has
as it's subject the URI http://soandso ??"

Why not?  That's how most PSIs do or will work, isn't it?  Or do you see 
it differently?

Cheers,

Tom P