Ten taxonomy myths is such an pleasently written article, it brings taxonomies in reach.
“Myth #1: A taxonomy can only be expressed as a hierarchical list of topics.
The implication of our definition is that every company will use multiple, interacting organization schemes (taxonomies). Some will be very concrete and may even be “invisible” except to computer programs (e.g. product codes). Others will be abstract, designed primarily for use by human beings (e.g. a list of topics on a departmental Web site).”
This is an exellent observation. Often I’ve seen arguments over which classification scheme to use, as if there is one ideal that all users can understand and meets all needs. But often the better answer is use several schemes. A CD site can have music type, artist and chronological classification schemes all mixed and matched– and often do. Why shouldn’t other sites support different user needs and mental models with multiple interacting schemes?