  The success of collaborative instruction in helping students achieve higher
grades in introductory science, technology, engineering, and mathematics (STEM)
courses has led many educators and researchers to assume these methods also
address inequities. However, little evidence tests this assumption. Structural
inequities in our society have led to the chronic underrepresentation of Black,
Hispanic, women, and first-generation students in STEM disciplines. Broadening
participation from underrepresented groups in biology, chemistry, and physics
would reduce social inequalities while harnessing diversity's economic impact
on innovation and workforce expansion. We leveraged data on content knowledge
from 18,791 students in 305 introductory courses using collaborative
instruction at 45 institutions. We modeled student outcomes across the
intersections of gender, race, ethnicity, and first-generation college status
within and across science disciplines. Using these models, we examine the
educational debts society owes college science students prior to instruction
and whether instruction mitigates, perpetuates, or exacerbates those debts. The
size of these educational debts and the extent to which courses added to or
repaid these debts varied across disciplines. Across all three disciplines,
society owed Black and Hispanic women and first-generation Black men the
largest educational debts. Collaborative instructional strategies were not
sufficient to repay society's educational debts.
