David Bullock is the man when it comes to Taguchi experiments for marketers.

Here are links to two articles that explore his philosophy and methodology:

Profiting from Consumer Behavior – from Black Enterprise Magazine (March 2007) (Downloads as PDF)

Taguchi Testing Can Triple Conversion – by Bob Bly, in DM News (December 8, 2006)

You can find All David All the Time online at www.DavidBullock.com.