Karen C. Timberlake is a Professor of Chemistry at Los Angeles Valley College where she has taught chemistry for over 30 years. She has been writing textbooks for more than 20 years and was the regional winner of the 1985 Award for Excellence in Teaching from the Chemical Manufacturers Association. Her educational interests include the investigation, development, and utilization of teaching methods that successfully impact the learning of chemistry. She has provided numerous workshops on student-centered learning strategies for teaching chemistry over the last decade. For ten years, she has been a visiting professor at UCLA where she has taught a preparatory class using non-traditional teaching methods.