Project Abstract Academic trajectories are established early, and children who enter school without the requisite readiness skills are at greatest risk for academic failure. Although language ability in early childhood is one of the strongest predictors of school readiness, many low-income children are markedly delayed in language ability. Dubbed the 30-million word gap, Hart and Risley (1995) demonstrated that children living in poverty hear substantially fewer words than their more affluent peers, and these findings have spurred national initiatives designed to increase the quantity of language input to young low-income children to establish positive early learning trajectories. However, exciting new research suggests these well-intentioned interventions may not have their desired impact if they do not also increase the quality of the communication foundation supporting language learning during early caregiver-child interactions. Hispanic children in Spanish-speaking and low income households are at significant risk for language delays and early academic failure, but there is little research regarding how to best support their language development and academic success. Our new findings regarding the importance of the quality of the communication foundation in the earliest years highlight how nonverbal and verbal qualities of parent-child interactions support the development of language skill and pave the way for developing optimal interventions. Spanish-speaking children are an important target for such interventions. An important preliminary step towards this goal, however, is to replicate this compelling research conducted with non-Hispanic African American and European American children with Spanish-speaking children. Building upon an existing study in Dallas that includes a large number of Mexican-origin Spanish- speaking families, we are uniquely positioned to address the following three aims: Aim 1. To refine the measurement methods for assessing the quality of the communication foundation so that they encompass culturally distinct patterns of parent-child interaction among Spanish- speaking Mexican-American families. Aim 2. To examine the relation between the quality of the early communication foundation and subsequent child language development among young Spanish-speaking Mexican-American children. Aim 3. To examine the relation between the quality of the early communication foundation and academic achievement in kindergarten and first grade among young Spanish-speaking Mexican- American children and whether it is mediated by early language development. Methods will include a comprehensive review and systematic modification of the existing rating protocol to capture those aspects of the early communication foundation among low-income Spanish-speaking mothers and their children. This revised rating system will be applied to existing data for a longitudinal cohort of low- income Mexican-American children selected from the Dallas Preschool Readiness Study (DPReP). Multivariate regression methods will be used to examine relations between the communication foundation assessed at age 2 with language and school readiness outcomes at ages 3 and kindergarten.