[xtm-wg] XTM-CMS: FW: Topic associations

["Wrightson, Ann" <Ann.Wrightson@sweetandmaxwell.co.uk>]

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• From: Daniel Rivers-Moore <daniel.rivers-moore@rivcom.com>
• To: "Wrightson, Ann" <Ann.Wrightson@sweetandmaxwell.co.uk>
• Date: Mon, 9 Oct 2000 10:01:00 +0100

Ann

It would be really helpful if you could resend the message below to the
xtm-wg with the prefix XTM-CMS. That way you are formally presenting this as
input to the conceptual modelling subgroup, with visibility to the whole
group.

We need to work during the coming week on the modification to the conceptual
model that will make associations into topics. It will be very helpful to
have your formal argument for this on record so we can refer to it in
support of our work. This is something we wanted to do anyway, but you have
added weight to the argument.

Best regards

Daniel

-----Original Message-----
From: Wrightson, Ann [mailto:Ann.Wrightson@sweetandmaxwell.co.uk]
Sent: 05 September 2000 08:42
To: 'daniel.rivers-moore@rivcom.com '; 'gdm@stepuk.com ';
'eliot@isogen.com '
Subject: Topic associations


HI folks...

Here's an interesting preliminary result from my ongoing investigation of
OHCO/TM  mediated information flow (using Barwise & Seligman's Information
Flow logic - see book of same name). 

1. In order for a topic map to serve as a "channel" of information about or
between one or more clumps of resources, then in this model there needs to
be an "infomorphism" from the resource-clump (which I'll call the domain)
and the TM. An infomorphism:
a) assumes that the types on the domain, and in the TM (=topics) are both
classifications (this is why I kept saying "classifier" at Paris...) 
b) has a function from types in the domain to types (=topics) in the TM 
c) has a function from particulars in the TM to particulars in the domain.

2. 1c is no problem - if links to resources are effective at all, this
happens.

3. 1b is the interesting one. For this to be a *function*, then a type in
the domain must, if it evaluates to a topic at all, evaluate to one topic.
So, if a TM is to be formally well-conditioned as a carrier of information,
a type in the domain which informally we might say maps to two topics, needs
to map to an association between them - and this association needs to be
itself a topic.

So, here is a (preliminary) good formal-modelling reason for topic
associations to be first-class topics. Also, whatever syntax and mechanism
is decided on for anchoring resources in XTM, the links must be capable of
interpretation as *functions* from the TM to the resource domain - though as
I said, I really don't see this will be a problem.

Enjoy!

Ann W.

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