English Learners (ELs)�students whose second language is English and who are not fully proficient in English�constitute the fastest growing portion of the K�12 student population. By 2025, according to U.S. government estimates, as many as one in four students in the United States will come from a home where a language other than English is spoken. Because many of these students tend to do poorly in school, teachers are encouraged to regularly use research-based practices to improve these students� academic achievement. Yet knowing which practices actually are research-based�that is, they are supported by research demonstrating impact on student outcomes�is not clear to many educators. This series of articles will help educators identify students� levels of oral and academic language proficiency, offer interactive and direct techniques to promote literacy development, and build and maintain effective programs for ELLs. This resource include 4 articles from the series `What Does Research Say about English Language Learners,` plus a study guide to facilitate group discussion.