In this highly theoretical book Engelmann and Steely breakdown the critical elements necessary for learning new actions and concepts. They diagram the necessary functions and systems for any organism or machine to perform an unlearned task. By analyzing the key components for the simplest organisms or machines to learn, Engelmann and Steely are able to construct meta-blue prints to better understand the simplest and most efficient way for humans to learn. The authors determined that once the foundation for unlearned responses is established learning mechanisms can be attached to the foundation, thus allowing for the demonstration of new, learned acts. The accumulation of new, learned acts will lead to higher order demonstrations involving concepts and language. The book is divided into four parts; performance of non-learning systems, basic learning, extended learning, and human learning and instruction. Additionally, the authors assess the implications of their model in relation to artificial intelligence entities.