This book for teacher trainees and practicing teachers contains programmed lessons that are designed to explain the theory and techniques of classroo m behavior modification. The first part deals with basic principles of behavior modification and includes chapters on how behaviors are learned, why they are maintained, and how they can be eliminated. It also contains a chapter on measuring behavior. The second part focuses on modifying classroom behavior. The chapters are divided into sets, each of which represents a different concept important to the chapter focus. Each set begins with a narrative designed to present new material. The programmed items were selected to give feedback to the reader regarding understanding of the material. In addition, the programmed items, or frames, incorporate classroom application of the concepts. The reader should respond to each of the items prior to checking the answer. Many of the sets contain exhibits which are excerpts from actual research done in the field of behavior modification. A list of suggested reading is included for those interested in learning more about the procedures and applications of behavior modification. (RC)