I must disagree with you. This book has very important things to say to teachers and others involved in education, but it is not ACCESSIBLE. It is difficult to read and very academic. Hattie makes references to ideas and concepts but does not explain them. For example, he makes references to Piagetian models of learning, but fails to fully explain what these are. He talks about implementing interventions and evaluating the impact, but never goes into details about the different interventions.
He needs to have the teacher reader in mind. As a teacher not only do I need the theory, I need the nuts and bolts of the practicalities. I also need a text that I can dip into that will give me information concisely and in an accessible manner. This is NOT what this text provides.