DAVID MATHEWS, PhD, is the chief engineer of Delta Performance Group. He is a consultant in product design and process optimization, specializing in new applications for statistical comparison techniques. He is an instructor in seminars at major universities and a technical advisor to engineers and statisticians. He also teaches at West Coast University and is a former adjunct associate professor in both the mathematics and physics departments at the University of Alabama in Huntsville. He is a member of the Eta Kappa Nu and Sigma Xi honor societies.