TABLE 1.

Comparison groups and outcomes measured for each of the three research questions in our study

Research questions	Comparison groups	Outcomea	Results
RQ1: Did students who passed Int Algebra (before it was required) earn higher grades and/or pass Intro Bio at a higher rate?	Preimplementation only (2008–2012) Group 1a: passed Int Algebra Group 1b: Did not pass Int Algebra	Course grades Probability of passing	Figure 1 Table 3
RQ2: Are pass rates and course grades in Intro Bio higher after students were required to have passed the prereq?	Group 1: Preimplementation (2008–2012) Group 2: Postimplementation (2013–2018)	Course grades Probability of passing	Table 4
	Group 1a: Preimplementation (2008–2012) passed Int Algebra Group 2: Postimplementation (2013–2018)
	Group 1b: Preimplementation (2008–2012) did not pass Int Algebra Group 2: Postimplementation (2013–2018)
RQ3: Did implementation of the math prereq negatively affect students?	Preimplementation (2008–2012) vs. postimplementation (2013–2018) Group 1: Intro Bio Group 3: Intro Chem Group 4: College enrollment (regular credit)	Course enrollment Demographic composition of the course	Figures 2 and 3Tables 5 and 6

^aAll outcomes were disaggregated by student identity, including PEER, FGN, Pell Grant recipient, and binary gender.