[topicmapmail] SAM question

[Lars Marius Garshol]

* HERBUEL Alain
|
| I've noted a topic may "represent" a subject via:
| * SubjectIdentifiers (SAM)
| * SubjectAddresses, and now subject locators (SAM)
| * SourceLocators (SAM)

Well, not really. A topic represents a subject. The URIs are about how
the topic *identifies* which subject it represents, which is something
else.

Source locators don't really tell you anything about the subject. They
just point to a place where the topic came from when it was read in,
or serve as a general identifier for the topic.

Subject locators point directly to the subject, so they definitely
identify the subject.

Subject identifier point at an information resource which describes or
indicates the subject, so they also identify the subject, but only
indirectly.
 
| On the other hand, we have in the section 3.4.1 : "Subjects may be
| identified in one or more of the following ways" :
| * subject identifier
| * subject address
| * subject indicator

Hmmmm. You have a point here. The typography makes it look as though
there are three alternatives, while there are actually just two (the
first two). I agree that's confusing. I've made a note of this and
will try to fix it in the committee draft.

Did that help?
 
| That makes me confused, and not sure to see the "cross reference"
| between How to identify a suject, and How to refer to it.
 
Hmmm. I'm not sure the specification uses both of those terms (I think
it only talks about identification), but I'd say that a subject
locator refers directly to the subject of a topic, and at the same
time identifies it. (Hard to point at something without also
identifying it.) A subject identifier just identifies the subject,
however, it doesn't refer to it.

Did that help?

-- 
Lars Marius Garshol, Ontopian         <URL: http://www.ontopia.net >
GSM: +47 98 21 55 50                  <URL: http://www.garshol.priv.no >