Addendum to Concepts First Paper: A Student Deficit Model is Untenable in Understanding a Demographic Grade Gap
This addendum shows that a demographic grade gap is best understood using a course deficit model rather than the more common student deficit model. Students from a concepts-first class took the same final exam as the three other classes that were offered at the same time so the grade gaps between different demographic groups from each class can be compared. It is found that students identifying as members of a racial/ethnic group underrepresented in physics had higher final exam grades than their peers from the same concepts first class rather than the usual case, lower exam grades than their peers, found in each of the other three classes. After controlling for demonstrated incoming understanding of calculus and Newtonian mechanics this demographic gap in the concepts first class is found to differ from that of the other three classes by over four standard errors. In addition, it's noted that while students' incoming understandings are useful in explaining within-group differences they do not explain between-group differences suggesting that a student deficit model does not explain (between-group) demographic grade gaps.