Book excerpt: Companion volume to the award-winning best seller Instructional Design Theories and Models, this book serves as a concrete introduction to instructional design for curriculum developers, teachers and teacher trainers, and students. Eight major theorists translate their works and theories into sets of instructional prescriptions; corresponding model lessons provide step-by-step illustrations of these theories. Instructional Theories in Action features: *overviews of the most important prescriptions and corresponding sample lesson plans written by the original theorists; *practical, concrete approaches to presenting the major strategies and principles; *model lessons focusing on the same objectives to facilitate comparisons of the theories; *numbered comments that identify which instructional prescription is being implemented at each point of the sample lessons; *chapter introductions, footnotes, and student study questions, and *clear identification and cross referencing of commonalities that are often masked by varying terminology.