[topicmapmail] Are Facets Really Simple After All?

[Thomas B. Passin]

I have been thinking that modeling facets could be fairly simple after 
all, despite the appearance to the contrary in the recent thread "Two 
Models of Facets".  Here is the idea.  I claim that facets are a way to 
classify something into multiple hierarchies, as opposed to just one 
hierarchy.

For example, say that we have a history facet and a geography facet. 
 From what I have seen, typically there will be a hierarchy of terms 
under "geography", such as "location".  That is, the "geography" facet 
is actually a hierarchical classification tree in its own right.  It 
just does not try to be all encompassing, but deals only with a 
Geography-related subset.

If this is a reasonable way to look at facets, then I do not see why 
using facets would be different in any essential way from classifying 
using a single hierarchy.  A given topic could be related to one of the 
faceted terms, say "location", by an association called, perhaps, 
"hasFacet".  You would find out which particular facet tree that 
"location" is in by walking up to the root of its tree to arrive at 
"Geography", whose type would be "Facet".  Of course, a real 
implementation would use some kind of shortcut to avoid actually walking 
the tree each time.

Is there something I am missing here, or is it really this simple?

Cheers,

Tom P