The Institute of Education Sciences and the National Institute of Child Health and Human Development (NICHD) are co-sponsoring a program of research on the development of English literacy in Spanish-speaking children. The goal of the Development of English Literacy in Spanish-Speaking Children research program (DELSS) is to stimulate systematic, multidisciplinary research that increases the understanding of the specific cognitive, linguistic, sociocultural, and instructional factors, and the complex interactions among these factors, that govern the acquisition of English reading and writing abilities for Spanish-speaking children and youth. The overarching questions guiding this research are the following: (1) How do children whose first language is Spanish learn to read and write in English? (2) Why do some Spanish-speaking children have difficulties acquiring English-language reading and writing skills? (3) For children whose first language is Spanish, which instructional approaches and strategies are most beneficial, at which stages of reading and writing development, and under what conditions?