Research-based assessments (RBAs) have served a central role in transforming STEM instruction by allowing instructors and researchers to measure the impact of instruction on student outcomes. Existing RBAs, however, are primarily fixed assessments that require instructors to administer them during the first and last week of class, score them, and analyze the results. The time and expertise required to do these steps prevents many instructors from using RBAs. The independent nature of these activities also inhibits large-scale data collection and research across diverse institution types. This Incubator project will support the creation of more sophisticated assessments that offer advantages to STEM instructors and education researchers. By creating and hosting assessments across STEM disciplines and K-16 grade bands, this Incubator project will support STEM instruction and create a large-scale database that can power novel STEM education research.<br/><br/>The Incubator activities include the creation of eight working groups that will address topics critical to ethical, large-scale data collection and the creation of diverse research collaborations. The first three working groups will include scholars and educators to develop reports on (1) the ethical collection and analysis of social identity data, (2) large-scale data collection with minors, and (3) effective large-scale partnership models. Reports from these working groups will guide the second phase of working groups focused on the needs of (4) K-12 administrators, (5) K-12 instructors, (6) two-year colleges, and (7) minority-serving institutions. The eighth working group will use the findings from the prior working groups to create a set of recommendations for expanding the Learning About STEM Student Outcomes (LASSO) platform and its network of users. The expanded LASSO platform will generate a large-scale, open-access database of grade K-16 STEM students' responses on cognitive diagnostic computer adaptive tests and a national network of community-based participatory research projects. <br/><br/>This project is supported through a partnership with the Bill & Melinda Gates Foundation, Schmidt Futures, and the Walton Family Foundation. Funding is also provided by the Discovery Research preK-12 program (DRK-12) program and the Improving Undergraduate STEM Education (IUSE) program at NSF. The DRK-12 program seeks to significantly enhance the learning and teaching of science, technology, engineering and mathematics (STEM) by preK-12 students and teachers, through research and development of innovative resources, models and tools. Projects in the DRK-12 program build on fundamental research in STEM education and prior research and development efforts that provide theoretical and empirical justification for proposed projects.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.