[faceted classification] User Centered Information Retrieval
(ttp://members.home.nl/mackelenbergh/no_hierarchies.htm)
Good description, general information and examples of faceted interfaces.
Added: 2/27/2004

eXchangable Faceted Metadata Language (XFML)
(www.xfml.org/)
XFML Core is an open XML format for publishing and sharing hierarchical faceted metadata and indexing efforts. XFML Core is lightweight and easy to implement, yet uniquely powerful.
Added: 10/30/2002

Lexonomy
(www.lexonomy.com)
Amy Warner's site. She specializes in taxonomy and metadata side of information architecture.
Added: 10/23/2002

Pareto's Principle: The 80-20 Rule
(library.shu.edu/HafnerAW/awh-th-math-pareto.htm)
More information on the much used "80-20 Rule", that states that "A minority of input produces the majority of results", which originated from Vilfredo Pareto, an Italian economist.
Added: 7/11/2002

[Taxonomy] Quiver
(www.quiver.com/)
Makers of auto categorization software: QKS Classifier.
Added: 2/26/2002

Article: Shallow vs. Deep Hierarchies
(www.ronscheer.com/html/readingroom3.html)
Article by Ron Scheer on entitled "Research on web site structure: Broad, deep, or what?"
Added: 1/27/2002