A growing number of American students are nonnative English speakers. These students are vulnerable to early school exit and schools are facing more and more such students each year. Presently, about 56% of all public school teachers in the United States have at least one English language learner (ELL) student in their class, but less than 20% of the teachers who serve ELLs are certified English as a second language (ESL) or bilingual teachers. What are the best methods and policies to help ELLs attain academic success? What are the most effective methods one can use when teaching ELLs? More broadly, what kind of training are teachers receiving or should they receive in order to help ELLs meet high academic standards? These questions were discussed at a National Invitational Conference, "Improving Teacher Quality for English Language Learners", convened November 13-14, 2003 in Arlington, Virginia. Sponsored by The Laboratory for Student Success (LSS), the Mid-Atlantic Regional Educational Laboratory, at Temple University Center for Research in Human Development and Education, the purpose of the conference was to provide insights and research-based information on how to improve the quality of teachers for all ELLs. The conference papers, general discussion, and work groups pointed to the conclusion that teaching informed by knowledge about language acquisition, cultural differences, and the social context of schooling can improve outcomes for English language learners and that increasing such knowledge among teachers, administrators, researchers and policymakers is both necessary and achievable. Strengthening links between evidence-based research and classroom teaching can benefit the growing population of English language learners in U.S. schools and those who share responsibility for educating them. This issue of "The LSS Review" contains the following: (1) Improving Teacher Quality for English Language Learners: Reports and Next-Step Recommendations from a National Invitational Conference (Hersh Waxman, Kip Tellez, and Herbert J. Walberg); (2) Critical Issues in Developing the Teacher Corps for English Language Learners (Patricia Gandara and Julie Maxwell-Jolly); (3) Training Teachers through Their Students' First Language (Liliana Minaya-Rowe); (4) Quality Instruction in Reading for English Language Learners (Margarita Calderon); (5) Successful School Leadership for English Language Learners (Elsy Fierro Suttmiller and Maria Luisa Gonzalez); (6) Lessons Learned from a Research Synthesis on the Effects of Teachers' Professional Development on Culturally Diverse Students (Stephanie Knight and Donna L. Wiseman); (7) Reculturing Principals as Leaders for Cultural and Linguistic Diversity (Augustina Reyes); and (8) National, State and Local Policies: Issues for the Preparation of Quality Teachers for Linguistically and Culturally Diverse Students (Eugene Garcia and Tom Stritikus). [For "The LSS Review. Volume 2, Number 4," see ED497148.]