This is one of the best books I have read on how students learn. Mayer's cognitive model, while limited to visual and auditory channels, provides a wealth of possibilities for maximizing the retention and understanding of information by students. Mayer practices what he preaches and writes a compelling, easy-to-understanding, summary of his ten years of research on the subject. The most important part of the book is that Mayer backs up his statements with data from the classroom. I can think of no other book that can make that claim. Like another reviewer said, if it doesn't change the way you teach or think about teaching, it should!