For all who are concerned with mathematics education (a set which should include nearly everyone receiving the Notices), KTEM is an important book. For those who are skeptical that mathematics education research can say much of value, it can serve as a counterexample. For those interested in improving precollege mathematics education in the U.S., it provides important clues to the nature of the problem. An added bonus is that, despite the somewhat forbidding educationese of its title, the book is quite readable. (You should be getting the idea that I recommend this book!)