PROJECT SUMMARY/ABSTRACT This project supports the ABCD-ReproNim Educational Program, which provides research training in responsible and reproducible analyses of data from the Adolescent Brain Cognitive Development (ABCD) Study. ABCD-ReproNim was established in 2020 as a NIDA-funded educational program and structured as a collaborative partnership between ABCD investigators and ReproNim, a NIBIB-funded P41 center for reproducible neuroimaging whose vision is to help researchers achieve more reproducible data analysis workflows and outcomes. With over 1K registered students and >15K YouTube views, the previous version of ABCD-ReproNim was well-received by the community and successfully achieved its goal to provide ABCD data training while promoting skill development in reproducible analyses that support efficient, re-executable design and FAIR practices. However, with advances in the field and increased data availability, we have identified gaps in our previous curriculum. First, while one of our lecture modules focused on ABCD's cultural and environmental variables, additional instruction is needed to train students on statistical and socioenvironmental considerations for responsible data use. Second, one of the most significant developments in emerging, population-based datasets, such as ABCD, is the availability of longitudinal data; however, many trainees lack hands-on instruction for appropriately handling multiple time points in complex, large datasets. Third, our previous students provided valuable feedback regarding challenges they experienced. We have addressed many of their concerns by providing a more flexible course schedule, expanding support by adding a fellows program, and increasing the quality and duration of hackathon preparation to prepare students to conduct their own data analysis projects. Moving forward, we propose to refine and extend the innovative ABCD educational approach. Participants will first receive didactic training across a 16-week online course that includes lectures, readings, and data exercises; at the completion of the course, participants will contribute to team-based, collaborative data analysis projects during a five-day hackathon at the host institution, Florida International University, in Miami, Florida. Through this research educational program, we aim to provide: instruction techniques that enhance the validity and reproducibility of research methods; a comprehensive understanding of the ABCD dataset; implementation of an inclusive training model; support of interdisciplinary, team-based collaborations; and dissemination of the course, project materials, and research findings. To achieve these aims, we have assembled an interdisciplinary team of instructors and evaluators that includes ABCD Study Investigators, ReproNim team members and collaborators, and non-ABCD/ReproNim researchers. Success will result in the generation of a cadre of investigators that are well trained in the techniques that suppor...