Teaching by Principles is a widely acclaimed methodology test used in language teacher education programs around the world. In this fourth edition, Dr. H. Douglas Brown and Dr. Heekyeong Lee offer a comprehensive survey of practical language teaching options firmly anchored in current research on second language acquisition and pedagogy. Features of the Fourth Edition A comprehensive update on current issues, new research findings, and innovative classroom teaching techniques, with additional and reworked chapters to reflect this information A description and analysis of new foundational principles, including: agency, identity, languaculture, communities of practice, embodied cognition, and self-regulation Pre-reading organizers at the beginning of each chapter Frquent statistics and pedagogical tips in each chapter Numerous classroom connections to stimulate practical applications of concepts and principles End-of-chapter group activities, discussion topics, and suggested additional readings A glossary of technical terminology