How can I present and organize complex taxonomy and groupings?

Question

Hi, this is a more generic question:

I am trying to find a way to classify a segment of data that have overlapping or sometimes multiple "broad categories."

I try to use "tags" as a way to allow some granularity, but I don't have a way to convey the more "top level" categories for people to browse.

For example, one of the vendors I am putting trying to classify does "Information Management" which isn't really a category of its own, it supports "Business Intelligence" but it isn't really Business Intelligence.

Not sure if people have thoughts or is the way to just look at how other people categorize these vendors in like directories...but wanted to know if poeple knew of both a way and, in particular, a presentation-layer / UI that makes it easier to "connect the dots" so to speak.

NOTE: This thread is a subset of what I am asking so additional elaborations would helpful:

http://stackoverflow.com/questions/281300/most-elegant-ui-for-categorizing-items

A more concrete direction: a non-proprietary way to create relationships like this:

http://www.thebrain.com/

Answer 1

A tag cloud, is the most ubiquitous way of displaying top level tags. Depending on your use they may be highlighted by popularity, or some other metric determined by a Folksonomy. Think Flickr or Del.icio.us