Re: Another round of subject identity crisis c.2011

Hi Andrew,

Now that we can assume that we have a common understanding of CTM,
back to your e-mail :)

[...]
> This isn't the type of example I was talking about, and yes, I agree
> with you that the only way to do this is via PSI's and the normal
> subject indicator model.

I see. Well, I haven't understood that you (ab)use CTM and subject
identifiers/locators to describe something outside of TMDM. If I see
something encoded in CTM/XTM my internal CTM/XTM processor maps that
automatically to TMDM. While I wait for rev. 2 of my internal CTM/XTM
processor I try to understand what your problem really is about.
Unsure if I understood it, though. I should have read your reference
[1] before giving an answer. :)

Regarding [1]: You state that x (a topic) is reified by y (a topic).
In TMDM-country x and y are replaced by z which represents the all
properties of x and y (since x and y represent the same
subject/topic). What would happen in Andrew-country if someone says x
reifies y? I assume that x and y are still different proxies. But
which relationship does "reifies" create? Do you create a proxy z
which represents the the union of x and y?

I think that your definition of "reifies/reified by" is important to
have common terminology since you use "reification" very often in your
problem description.

[...]
> If I wanted to talk about a proxy that reifies an image of Dublin,
> who defines the rules by which the type and properties are
> determined?  This picture is from 1942 and this one is from 2011 of
> the same street.  There has to be a way to reference a collection of
> properties about a subject (so maybe I should've included
> <http://.../Dublin> as well) and tie those efficiently to the
> resource from which they were derived.

You'd define an ontology/a legend which tells you that it's the same
street at the moment t1 and at the moment t2. Probably you wouldn't
have to state that: Simply use the IRI of of picture A and the IRI of
picture B and make statements about it. Someone may recognize that pic
A and B represent the same street and either merge the proxies/topics
since they represent the same street or create another
proxy/association between them. It depends on your individual world
view.

If I take a picture of a house you walk by mistake into the scene, I
wouldn't care about you, publish my picture and use the IRI to state
"I talk about the subject 'house' depicted at IRI XY". Someone sees
you at the picture and says "I talk about the person 'Andrew' depicted
at IRI XY". It's a matter of trust/context to identify the concrete
subject and I doubt that Topic Maps or other any technology can
resolve this conflict. It depends on your perspective. In TMDM-country
this may become a problem since a Topic Maps engine would blindly
merge the subject identifier XY and we don't have a a (standardized)
unmerge operation. Other, fine-grained technologies may avoid the
merge and create a dynamic/user-dependent view on the subject.

A possible solution of this conflict are PSIs which are meant to
describe a subject uniquely. If we wouldn't take the picture but your
e-mail address to identify you and a geo pos to describe the house,
and create relationships to the same picture (also a topic/proxy),
we'd avoid accidental merging operations to some extent.

... another long mail without solving your problem? :)

[1]
<http://www.infoloom.com/pipermail/topicmapmail/2010q4/008728.html>

Best regards,
Lars
-- 
Semagia 
<http://www.semagia.com>

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