Course Background • This research focused on students in Biology 180, the first course in a three-quarter introductory biology sequence designed for undergraduates intending to major in biology or related disciplines at the University of Washington. This course is a five-unit course offered every quarter. • The data come from six quarters when one of the authors (S.F.) was the only instructor. The course included four 50-min class sessions and a 2-hour or 3-hous laboratory session each week. In every quarter there were 400 exam points possible; all exam questions were written,

Student Demographics • During the study period, most students had to complete a chemistry prerequisite before registering for Biology 180. The majority of students were in their sophomore year. • In the most recent quarter analyzed here, the course’s demographic makeup was 61.1% female and 38.9% male; 46.7% Caucasian, 38.5% Asian-American, and 7.4% Under-represented minorities (African-American, Hispanic, Native American, or Pacific Islander), with 7.4% of students declining to declare their ethnicity. • In addition, 16.4% of the students were in the UW Educational Opportunity Program, meaning that they were identified as economically or educationally disadvantaged. • These demographic data are typical across the quarters and years of the study.