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 EditionA comprehensive update on current issues, new research findings, and innovative classroom teaching techniques, with additional and reworked chapters to reflect this informationA description and analysis of new foundational principles, including: agency, identity, languaculture, communities of practice, embodied cognition, and self-regulationPre-reading organizers at the beginning of each chapterFrquent statistics and pedagogical "tips" in each chapterNumerous "classroom connections" to stimulate practical applications of concepts and principlesEnd-of-chapter group activities, discussion topics, and suggested additional readingsA glossary of technical terminology