While this 1999-2000 edition is a little dated today, it provides useful models, instructional strategies, and examples for teachers to think about and improve differentiation of instruction. The central model connects levels of learning and elements of curriculum. The topic of study is made up of key facts, organizing concepts, guiding principles, associated attitudes, and essential skills. Teachers must include all those components and differentiate the content, process, and product according to students' readiness, interests, and learning profile. This is a great way to think about differentiation, then instructional strategies–whether from this book or elsewhere–can be utilized within the model to effectively meet diverse students' needs. This is definitely worth a read for teachers at all grade levels in all content areas.