poor and minority students are disproportionately likely to have attended low-performing schools and to have missed out on the rich academic and extracurricular offerings familiar to their wealthier white classmates, thus arriving on campus with less background knowledge. This is a problem, since research has demonstrated that we learn new material by anchoring it to knowledge we already possess. The same lecture, given by the same professor in the same lecture hall, is actually not the same for each student listening; students with more background knowledge will be better able to absorb and retain what they hear.Active-learning courses deliberately structure in-class and out-of-class assignments to ensure that students repeatedly engage with the material. The instructors may pose questions about the week’s reading, for example, and require students to answer the questions online, for a grade, before coming to class. This was the case in an introductory biology course taught by Kelly A. Hogan at the University of North Carolina at Chapel Hill. In a study conducted with Sarah L. Eddy of the University of Washington, the researchers compared this “moderate structure” course (which included ungraded guided-reading questions and in-class active-learning exercises in addition to the graded online assignments) to the same course taught in a “low structure” lecture format.