One result of the all-time high in population mobility is that in many school systems monolingual and monocultural students are the exception rather than the rule, particularly in urban areas. This shift in demographic realities entails enormous challenges for educators and policymakers. What do teachers need to know in order to teach effectively in linguistically and culturally diverse contexts? How long does it take second language learners to acquire proficiency in the language of school instruction? What are the differences between attaining conversational fluency in everyday contexts and developing proficiency in the language registers required for academic success? What adjustments need to be made in the curriculum and in instruction and assessment to ensure that second language learners understand what is being taught and are assessed in a fair and equitable manner, and how long should schools wait before including them in high-stakes national examinations and assessments? What role should be accorded to students' first language in the curriculum? In addressing these issues, this volume focuses not only on issues of language learning and teaching, but also highlights the ways in which power relations in the wider society affect patterns of teacher-student interaction in the classroom. Effective instruction will inevitably challenge patterns of coercive power relations in both school and society. The book is divided into three parts and ten chapters. Hundreds of references and a highly detailed subject index is included. (Author/KFT)