  When assessing student work, graders will often find that some students will
leave one or more problems blank on assessments. Since there is no work shown,
the grader has no means to evaluate the student's understanding of a particular
problem, and thus awards 'zero' points. This practice punishes the student
behavior of leaving a problem blank, but this zero is not necessarily an
accurate assessment of student understanding of a particular topic. While some
might argue that this practice is 'fair' in that students are aware that they
can't receive points for problems they don't attempt, we share evidence that
this practice unequally impacts different student groups. We analyze 10 years
of UC Davis introductory physics course databases to show that different groups
of students (by gender, racial/ethnic group, first generation, etc.) skip
problems, and entire exams at different rates. We also share some implications
for grading and teaching practices.
