A recent study of undergraduates across five Big Ten research universities found that women in large classes in biology, chemistry, physics, accounting, and economics performed about a third of a grade point lower (e.g. A- to B+) than similarly situated men. Understanding the basis for this gendered performance difference has the potential to contribute to a better understanding of the poorer persistence patterns of women and other demographic groups in STEM, and to the development of means by which those differences can be eliminated. This grant funds an effort by University of Michigan physicist Timothy A. McKay to assemble a broad coalition of university collaborators to jointly undertake further research and interventions. The acronym for the project is SEISMIC, for the Sloan Equity and Inclusion in STEM Introductory Courses project, appropriately reflecting the opportunity for powerful disruption of an entrenched system. SEISMIC will bring together 11 institutions, each contributing a team of approximately 10 faculty members, students, and staff. The teams will examine all introductory STEM courses on all campuses through current analytics and engage in parallel data analysis, data sharing, coordinated experiments, a continuous exchange of speakers (about 60 per year), and extended annual summer meetings. Attention will be paid to the diversity of institutions chosen. Gender will continue to be an object of study, and the project will also examine other student demographics including race/ethnicity, first-generation (first-gen) college students, and various forms of intersectionality, e.g., Latina women or first-gen men. A planning meeting and three annual collaboration summer meetings will be held to accelerate research, build community, and enhance the spread of ideas. Results will be disseminated broadly through presentations at national professional meetings and publication in several peer-reviewed articles that will reach broad STEM and STEM-education audiences.