iv About the Authors John R. Walker is the author of thirteen textbooks and has written numerous magazine articles. Mr. Walker completed his undergraduate studies at Millersville University and has a master’s degree in Industrial Education from the University of Maryland. He taught industrial arts and vocational education for more than 32 years, including 5 years as Supervisor of Industrial Education. He also worked as a machinist for the US Air Force and as a draftsman at the US Army Aberdeen Proving Grounds. Bob Dixon is a Professor and Head of the Engineering Technology Department at Walters State Community College in Morristown, Tennessee. Dr. Dixon holds bachelor’s and master’s degrees in Engineering Technology from East Tennessee State University, a master’s degree in Industrial Engineering from the University of Tennessee, and a doctorate in Educational Leadership from East Tennessee State University. Prior to entering the education field, Dr. Dixon spent over 20 years in industry working in a variety of machining, manufacturing, and engineering positions. He is an ATMAE Certified Senior Technology Manager and recipient of the 2005 ATMAE Outstanding Faculty of Industrial Technology Award for Region 3.