Project Summary/Abstract This exploratory experiment is designed to determine the extent to which the socialization experiences and social, behavioral, and linguistic skills of preschoolers with language impairment (LI) can be improved. We implement a peer-mediated intervention in 30 inclusive preschool classrooms, randomly assigned to treatment or control in a wait-list design experiment. A focal child (n = 30) is identified in each classroom, representing a child with LI (3 to 5 years of age) who exhibits the poorest pragmatic-language skills and highest level of social exclusion in the classroom. Over a 12-week period, the focal children will receive peer-mediated intervention from identified peers, who use strategies to engage the focal child socially during center time, as supported by a classroom facilitator (teacher, aide). Outcomes of interest include the overarching classroom social network and its embedded socialization processes (e.g., frequency to child-to-child interaction), the focal child’s interactions with peers and exposure to peer talk, and the focal child’s social, behavioral, and linguistic skills. The study employs state-of-the-art social network analyses to represent the classroom network at the child, dyad, and network level and is dynamically modeled over the academic year using advanced location-tracking technologies and voice-activated recorders to capture incoming and outgoing peer talk for the focal child. We anticipate the results of this study to yield significant theoretical and scientific impact. Theoretically, we propose that improved socialization experiences in the preschool classroom can disrupt the social exclusion and peer maltreatment experienced by children with LI, leading to accelerated growth in social, behavioral, and linguistic outcomes for children with LI. We can test the mediated relations between peer-mediated intervention and child outcomes to assess these direct and indirect pathways. Scientifically, our multidisciplinary team is poised to pursue best-in-class health-relevant research integrating complex technologies and dynamic modeling of social networks to improve intervention design and conceptualizations, and will provide proof-of-concept for integrating these approaches into future research on the socialization of children and others with disabilities.