Too often, the needs of English language learners are met with simplified curriculum and lowered expectations. What would happen if instead classrooms were organized to honor the promise of these students by increasing rather than decreasing the intellectual challenge of instruction, by increasing the support such challenge requires, and by increasing students' active engagement with their own learning? This book is the result of a decade-long effort in school districts such as New York City, Austin, and San Diego to implement challenging instruction that is designed for classrooms that include English learners and that raises the bar and increases engagement for all learners. Classroom vignettes, transcripts of student interactions, and detailed examples of intellectually engaging middle school and high school lessons provide a concrete picture of the instructional approach developed by coauthor Aída Walqui, founder and director of WestEd's Quality Teaching for English Learners (QTEL) initiative. Underlying the QTEL approach and giving it coherence and power are three strands of instructional theory--cognitive psychology, sociolinguistics, and sociocultural learning theory. Coauthor Leo van Lier, internationally recognized author, linguist, and sociocultural theorist, lays out through clear and frequently wry examples just what these theories have to offer the classroom teacher, in particular the teacher of English learners.