Excel-erated Learning by Pamela J. Reid, Ph.D. If you are interested in knowing more about learning theory and what positive reinforcement, positive punishment, negative reinforcement, negative punishment and all the other learning theory terminology mean and are all about, then I highly recommend this book to you. Of all the books I have read, this one most clearly explains all the learning theory lingo in layman's terms. But for most people who just want to know what to do with their dogs and do not care about all the terminology, you can skip this one. For learning nerds only!