The truth about taxonomies.

• Author: Bruno, Denise

At the Core

This article

* defines a taxonomy

* explains how an organization can use and develop taxonomies

* identifies types of taxonomies

Imagine opening up file cabinet drawers, credenzas, or desk drawers and seeing papers and materials piled up and scattered with no rhyme or reason. Imagine information on a computer stored in one or two big dumping grounds according to the name of a person or titles that only make sense to the creator, with no breakdowns according to specified groupings. Chances are, in either case, it will take a long time to locate files. And what happens when there are new items to add? The valuable space being occupied in these examples is not being used and organized to provide the best benefit in terms of space and time efficiency.

In an office situation, a taxonomy or classification scheme to organize the paper and/or electronic documentation is required. Most organizations use some form of structure to manage their paper documentation. This may or may not be a documented procedure. It may or may not be a system that is widely understood by all employees. It may or may not reflect the business needs of the organization. When it comes to the electronic information in most organizations, it is often every computer or shared drive for itself. Often there are no guidelines or procedures for how these repositories of corporate information and knowledge are to be handled. Organizations frequently overlook the management of one of their most important business assets--information. Information is the fuel that keeps an organization running smoothly. Why then do organizations not give more time and attention to the management of this important asset? Unfortunately, no one discusses the need for better management of information until a crisis hits.

WHAT IS A TAXONOMY?

According to www.whatis.com:

Taxonomy (from Greek "taxis" meaning arrangement or division and "nomos" meaning law) is the science of classification according to a pre-determined system, with the resulting catalog used to provide a conceptual framework for discussion, analysis, or information retrieval. In theory, the development of a good taxonomy takes into account the importance of separating elements of a group ("taxon") into subgroups ("taxa") that are mutually exclusive, unambiguous, and taken together, include all possibilities. In practice, a good taxonomy should be simple, easy to remember, and easy to use. Another definition, according to Jean Graef of the Montague Institute is:

"... structures that provide a way of classifying things--living organisms, products, books--into a series of hierarchical groups to make them easier to identify, study, or locate. Taxonomies consist of two parts--structures and applications. Structures consist of the categories (or terms) themselves and the relationships that link them together. Applications are the navigation tools available to help users find information." Other terms associated with taxonomy development and implementation are controlled vocabulary, thesaurus, and user warrant. A controlled vocabulary is an indexing language (i.e., a standardized set of terms and phrases authorized for use in an indexing system to describe a subject area or information domain). A thesaurus is a type of controlled vocabulary that shows the hierarchical (parent-child), associative (related), and equivalent (synonymous) relationships among terms. Often, controlled vocabulary, thesaurus, and classification structure (taxonomy) are used interchangeably. User warrant is a justification for the representation of a concept or for the selection of a preferred term because of individual user needs.

In essence, a taxonomy is a hierarchical classification of headings constructed using the principles of classification, and a thesaurus supplies the commentary and links to navigate the taxonomy. In today's information-dependent environment, where we are receiving, accessing, and using information in its many forms, it is absolutely imperative that there are well-defined and documented structures in place. This ensures that the person needing the information receives it in the timeframe required.

However, the reality in most organizations is a

* ack of standardized procedures

* "stovepipe" approach to information process

* ack of an information-sharing culture

* proliferation of legacy systems

Taxonomies can provide:

1. Identification--The taxonomy can help control the glut of information and identify where information should be stored by filtering, categorizing, and labeling information.

2. Discovery--Additional information on a topic can be inferred by seeing where the entry is placed in context within the taxonomy and provide serendipitous guidance to the person working on the issue.

3. Delivery--The taxonomy can improve the retrieval process. The use of the taxonomy's controlled vocabulary enhances searching via browsing. The use of navigation paths or "breadcrumbs" based on the taxonomy's hierarchy provide context and enhance searching via free text. For example, if a free text search returns 100 hits for the word "bridge," the navigation path for each hit provides the context required to show whether the record refers to a structure, a card game, or financing. It is not necessary to open each returned record to see how the word "bridge" is used.

   In addition to performing these basic functions, Graef suggests "A taxonomy should also inspire trust. The user should feel confident that the taxonomy will help him find the information he seeks--if it exists ... As more information gets into electronic format and becomes available over global networks, it gets harder to ensure that any one taxonomy is both sufficiently specific and comprehensive."

   CLASSIFICATION THEORY

   Although many logically different structures address taxonomies or classifications, two of the most widely known are the generic relationship and the whole-part relationship. In her article, "The Role of Classification in Knowledge Representation and Discovery," Barbara H. Kwasnik defines these relationships and provides the pros and cons of each.

1. Generic Relationship (Genus/Species) This theorem is probably the most true of all taxonomies. It adheres to strict structural requirements and contains the following properties: genus/species, inclusiveness, inheritance, transitivity, rules for association and distinction, and mutual exclusivity. The following, taken from the Medical Subject Headings (National Library of Medicine), is an example of such a structure:

   * Eye Diseases

   * Conjunctival Diseases

   * Conjunctival Neoplasm

   * Conjunctivitis

   * Keratoconjunctivitis

   * Corneal Diseases

   Genus/species: A true hierarchy has only one type of relationship between its super and subclasses, which is known as the "IS-A" relationship. In a generic relationship, keratoconjunctivitis is a kind of conjunctivitis, which in turn is a kind of conjunctival disease, which in turn is a kind of eye disease.

   Inclusiveness: The top...