[tm-pubsubj-comment] Strawman Issue 2: PSI topics versus other topics

[Mary Nishikawa <nisikawa@fuchinobe.oilfield.slb.com>]

At 04:33 PM 2/21/02 +0100, Steve Pepper wrote:

>OVERVIEW OF THE PSI SET TOPIC MAP
>
>* Issue: If we use topics as PSIs, should it be possible to distinguish
>topics that are *intended* to be used as PSIs from other topics (in the
>same map) that are not?
>
>I think it should. The mechanism I have used is a self-referential
>subject identity. For example, the topic "ontopia" has its subject
>identity defined through a subject indicator reference with the URL
>
>   "http://psi.ontopia.net/ontopia/ontopia.xtm#ontopia"
>
>-- in other words, it points to itself. Even an application that has not
>retrieved the topic map from its canonical location can know that this
>is the case because the "identifier" of the topic map is set to the URL
>
>   "http://psi.ontopia.net/ontopia/ontopia.xtm"
>
>through an occurrence on the "topicmap" topic. (More about this later.)
>
>I'm not sure this is a good solution for distinguishing between PSI
>topics and non-PSI topics, but I got it for free, because I am using
>that subject indicator reference to specify the identifier of the
>published subject. (See the subhead "IDENTIFIER" in the next section.)
>
>I'm not sure how else we might differentiate PSI topics from non-PSI
>topics. Creating a PSI for PSIs and making the PSI topics instances of
>this type is not an alternative, because that would amount to saying
>that, say, (the company) Ontopia is an instance of the class Published
>Subject Indicator, which it obviously is not.

  I am not so sure about the "self referential" subject identity. Are you 
saying that the  subjects that would have the self referential identities 
would always be the published ones and those that do not, would be the others?

The published subjects and those that were not would be in separate maps? 
The ones that have metadata associated with them would be the published 
ones? What happens when these maps are merges. This needs some 
experimentation, I think.

-- Mary