Overall Project summary Rapid growth in access to digital media is accompanied by a scarcity of research examining complex, real-time family media context and sociocognitive outcomes, driven in part by a lack of comprehensive measurement tools. To meet this challenge, the PI’s interdisciplinary research team developed a multi-method, scalable, cost-effective toolkit called the Comprehensive Assessment of Family Media Exposure (CAFE) Toolkit. The toolkit is designed to capture the content and context of early media exposure (Barr et al., 2020; Radesky et al., 2020a). While this toolkit represents a substantial step forward in characterizing the family media ecology, progress in understanding the effects of media exposure on child outcomes has also been limited by the lack of large and representative longitudinal datasets, the difficulty of tracking quality of content in an ever-changing media environment, and the lack of a mechanism to rapidly share and analyze results in a theoretically driven manner. To overcome these limitations in the field, the overarching goal of this Research Program proposal is to examine trajectories of media use - characterizing the context, content, and problematic uses of media - in 1200 children aged between 1 to 7 years, assessing temporal associations with emotion regulation and social competence using a cohort sequential design. The Research Program includes three longitudinal studies, collecting data in three cohorts that span the entire age range (1-3, 3-5, 5-7 year olds). The work described in this application will also produce research infrastructure to increase the efficiency of coding the quality of media content, a bottleneck in the field. Finally, the data will be integrated, shared, visualized and analyzed in a shared analytic research hub. The proposed research is significant because it would be the first synergistic effort to utilize a comprehensive assessment of the family media ecology in a large, diverse, longitudinal sample to identify antecedents of problematic media use in early childhood as well as specific media use patterns that support social and emotional development in early childhood. The proposed work is innovative because it (1) uses a multi-method, comprehensive assessment of the family media ecology; (2) applies an ecological lens to study media effects and socio-emotional development within the family system; (3) maximizes impact and efficiency with synergistic science; (4) streamlines content coding in an ever-changing media environment; and (5) builds a collaborative platform for cleaning, integrating, and analyzing shared data for reuse.