[sc34wg3] SAM-issue term-subject-identity

[Lars Marius Garshol]

* Ann M. Wrightson
| 
| 1. Yes, the term is needed, since it is a "co-ordination point" for
| the various arguments about when topics should be merged - [...]

That's a possible use case. So we would use it to write sentences like
"topics are merged when they have the same subject identity"? If so, I
feel that the term (rather than its definition, as Marc claims) is
broken, and should be replaced.

To say "topics are merged when they have the same formal subject
identification" sounds better, doesn't it?

| 2. The notion of subject identity should be carefully and explicitly
| defined, since this definition determines a v. important aspect of
| topic map behaviour - including the vulnerability of a topic map to
| rogue added information.

Absolutely. And it needs to be defined in such a way that it is clear
that there can be more than one way to identify a topic's subject.
SAM provides some alternatives, but TMCL may provide more...
 
| 3. The XTM definition is a good start, in that it mentions both being
| identical and being distinct.
| IMO arguments to date have focussed on the benefits of identifying
| subjects which are the same (presumably from the viewpoint of the
| (author of the) merged topic map), rather than on the risks of
| spurious identification of subjects which are distinct.

True. I am not sure what practical consequences it has for the text of
the standard, however.
 
| 5. Here's my candidate for a sufficient case for considering two
| subjects to be identical:
| 
| Two subjects A & B are identical if (and only if): considering all
| information pertaining to A to pertain to B, entails no loss of
| ability to discriminate distinct situations in the "real world"
| (that is, the perceived-world of the machine-or-human agent doing
| the merge) In this definition, an item of information pertaining to
| A is, crudely, a topic characteristic of A; "situations" are bunches
| of items of information, i.e., when modelled in a topic map,
| collections of topic-characterstics-on-a-topic.

This is definitely more RM-y that SAM-y, I would say.  The SAM will
need to base it on specifics and say exactly what is involved. To have
a more general policy-like definition in the RM is sensible, however.

-- 
Lars Marius Garshol, Ontopian         <URL: http://www.ontopia.net >
ISO SC34/WG3, OASIS GeoLang TC        <URL: http://www.garshol.priv.no >