Absolutely invaluable! This very thin book is a beta study that accumulates the findings of numerous research projects and condenses it into a terse, concise user's manual. If anyone really needs to know, it works like this: first, all of us enter the arena, the learning event carrying prior knowledge and experience--this a nod to constructivist learning models; second, all valid learning must be framed in a context of theory combined with practice; and third, the best learning allows for strategies that enable the learner to monitor and reflective evaluate his or her own progress--it internalizes it.
I underlined my copy. I refer to it over and over. I highly recommend it to anyone who is even remotely interested or connected to learning, who has learned once and would like to again, or who is willing to learn afresh.