From his infectious enthusiasm for the Mindstorms NXT System it might be easy to guess that Laurens Valk was introduced to Lego Robotics at age 13 just five short years ago. But, from the careful logical pedagogy of this book and his interesting approach mixing successively more advanced robots intermixed with a clearly arranged taxonomy of parts, programming tools and motor/drive train and sensor categorization, I would have imagined that this book was written by an excellent teacher with many years of experience bringing engineering concepts to youthful learners.  Not only does the book offer a clear top-down beginning to end approach to both the NXT Parts Architecture and NXT-G Programming Language while combining this end-to-end approach with interesting projects of increasing difficulty, but he stimulates the reader with building and programming challenges to increase their skill at independent thought in robot building and programming.  Just how far and how thoughtfully Laurens' teaching approach goes is indicated by by his unique system of flowcharting/state diagrams which both provides the logical decisions involved in programming this system with a graphical correspondence to the NXT-G Programming language.