David Klein is a Senior Lecturer in the Department of Chemistry at The Johns Hopkins University where he has taught organic chemistry since 1999. Having worked with thousands of students, he has intense first-hand knowledge of how they learn and the difficulties they encounter. He received his bachelor’s degree in chemistry from The Johns Hopkins University and his PhD from the University of California at Los Angeles under the supervision of Professor Orville Chapman. Motivated by his experiences teaching organic chemistry as a graduate student at UCLA, David wrote Organic Chemistry as a Second Language (John Wiley & Sons, 2004, updated 2nd edition published in 2008), which has become a highly valued student study resource. David has received numerous teaching awards at both UCLA and Johns Hopkins for his unique, skill-building approach to organic chemistry instruction. David is married, with five children, and enjoys skiing, scuba-diving, and Tae Kwon Do.