[Sigia-l] multi-faceted & topic map

[Peter VanDijck]

> I'm hoping to pick the collective brain. I'm part of teams that's building
> an extranet from the ground up. The client has specifically asked for a
> taxonomy. 

The tide is turning :)

> In thinking about a solution, they are prime candidate for
> multi-faceted classification.

Most websites are ;)

> As a I was digging for ideas on execution, topic maps were thrown into the
> research mix. I'm left a little confused as to how they work with the
> classification structure. Are the two mutually exclusive? And if not, I'm
> not quite sure how they work together.

Here goes.
Almost any classification structure can be expressed as an XML topicmap.
You can also express almost any classification structure as RDF for
example, another format for metadata. The question is why do you want to
do that.

Topicmaps are two things: a certain, very generic structure of metadata,
and an XML format. The XML format is called XTM - you don't have to
worry about that in this stage. The structure that topicmaps impose is
what you need to understand first.

Topicmaps define a very generic, powerful structure for certain types of
metadata - the classification type. You define lots of topics, and then
you define relationships between them and other funky things. Topicmaps
are more complex than just a simple tree or a simple hierarchical
faceted classification (although you can certainly express those as a
topicmap) (read up on topicmaps to better understand the structure they
provide). 

The question is: is using a topicmap structure to define the taxonomies
of my site useful? Topicmap driven sites are often VERY cross
referenced, very dynamic. You probably don't need that level of
complexity. What you (maybe!! - it depends) need, as for classification
structures, may be something like this:

- 1 main classification tree used to generate navigation. Simple stuff.
The classification scheme is often TOPICS. Or you might have 2 main
trees. Maybe TOPICS and BRANDS. (It all depends - maybe your tree is
TOPIC-BRAND or TOPIC-TASK)
- a few alternative classification trees that generate navigation like
(see also) or personalization. Classification schemes using these trees
could include LOCATIONS or EVENTS, for example.
- a controlled vocabulary structure for your search engine (a simple
structure like 'word - equal words - preferred url' will get you far.)

No need to use topicmaps for these structures for now. Often, the most
useful way to implement this is to simple design the structures and then
put them in a database and run the site from that. No need for XTM or
XFML or what have you. This is often misunderstood. Remember, you can
always express these structures in a topicmap, but there has to be a
need for it (for example interaction with other systems could be a need
that could be solved by exporting your structures as XTM). 

Good luck, hope this was somewhat helpful.
PeterV