This Study Snapshot highlights key findings from a study that examines up-to-date information about evidence-based practices that are essential for early childhood educators and policymakers as they support preschool children's language and literacy development. The study used a process modeled after the What Works Clearinghouse (WWC) methodology to systematically identify effective early childhood curricula, lesson packages, instructional practices, and technology programs in studies conducted from 1997 to 2017. The findings revealed that instruction that teaches a specific domain is likely to increase performance in that domain. Interventions that teach language exclusively might be more beneficial when conducted in small groups or one-on-one than in larger group sizes. [For the full report, see ED613947. For the appendixes, see ED613954.]