One of the challenges to educating English-language learners (ELLs) is ensuring that students become literate in their native language--something that experts say is important for their success in English and other subjects--and learn sufficient English skills before the middle grades, a critical transition point because of the increasingly difficult academic content that students are expected to master in English. While Chicago Public Schools' (CPS) bilingual programs have fallen short in quality, most ELLs do make the leap out of bilingual education by 3rd grade. But of the nearly 64,000 bilingual students in CPS, 12% are in the middle grades and have been in bilingual education since their early school years. Research shows that long-term bilingual students are more likely to fall behind their peers in high school. These students are also more likely to be in special education. Many schools nationwide lack the resources to teach these students, including teachers with the right training. If current trends in population and achievement continue, up to one-quarter of all U.S. students may fail to become proficient enough in English to succeed in school before they graduate or worse, drop out of high school, says Arizona State University bilingual education expert Eugene Garcia. CPS is encouraging schools to increase programs that help students develop their native language, because of "the positive academic, social, and cultural benefits for students who maintain higher levels of language and literacy development in their first language while learning a second language."