[topicmapmail] Are Facets Really Simple After All?

[Murray Altheim]

Thomas B. Passin wrote:
> Murray Altheim wrote:
> 
>>...But I can't
>>imagine that a "correct" occurrence of the Paris Topic would be
>>"2003-11-23T11:34:55", "245,190", or "#bce033" (i.e., the creation
>>date of the Topic in my application, the location of the Topic
>>node in my TouchGraph visualization, or the colour of the displayed
>>node, resp.). That just isn't right.
> 
> I agree, and there is a good reason why is just isn't right.  Those 
> things belong to a UI proxy for the topic, rather than to the topic 
> itself.  If you had created a topic for the screen object, then they 
> *would* be suitable occurrences for *that* topic.  The "real" topic 
> could be related to its UI proxy by means of an association.
> 
> I do not yet have an opinion about whether such UI proxy topics would be 
> a good way to share topic map layout, but this notion clears up the 
> "not-rightness" of the occurrences.

But Tom, it's really more than that. It's not just UI stuff, but
any meta-information that might be considered about the Topic,
but not sharing the subject of the Topic. So, in addition to the
UI stuff in my example (of which 'created date' is not really UI),
there'd be any of the relevant Dublin Core-style metadata such as
creator, contact person, contributor, resource type, identifier,
source, rights, medium, version number, etc.

If you generalize from a "UI proxy" to simply a "proxy", you're
basically suggesting a container for any kind of Topic metadata
that is connected to but not contained within the Topic. If for
each Topic we wanted to store ten kinds of metadata, and we had
twenty Topics in our Topic Map, we'd end up with 200 <topic>
elements. That sounds like a mess. I think that would actually
be appropriate if we were creating an FC system, but for storage
of Topic metadata/properties of the RDF ilk, maybe we could put
it all within just one second Topic whose purpose is explicitly
to store Topic metadata. Its type would be recognized as such,
and we'd only double our number of <topic> elements. The subject
of each of those proxy Topics would basically be "the metadata
of Topic X", and there'd be a "hasProperty" Association between
them (as opposed to a "hasFacet" property for facets).

This seems to me to be cleaner, do no semantic violence, and
still be a reasonable solution in terms of XTM syntax.

What'dya think?

Murray

......................................................................
Murray Altheim                    http://kmi.open.ac.uk/people/murray/
Knowledge Media Institute
The Open University, Milton Keynes, Bucks, MK7 6AA, UK               .

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