Two-way and Monolingual English Immersion in Preschool Education: An Experimental Comparison

Preschool programs in the United States have sought to keep pace with the rapidly growing number of children who are English language learners. For example, the Hispanic population in public school and Head Start programs is 25-30 percent. These children present challenges and opportunities for public preschool programs. This NIEER study addresses the gap in research available to identify which approach -- monolingual or dual language (bilingual) -- offers the most effective support for both English and Spanish language acquisition in preschool.