Computer science courses employ a variety of assignment deadline policies ranging from strict policies where no late submissions are accepted to flexible policies where extensions, sometimes lengthy ones, are permitted without grade penalty. Many instructors have moved towards increased flexibility for students to alleviate pressure, help students succeed, and better manage the administrative burden of granting extensions. Using data from eight offerings of three computer science courses, we compare assignment submission rates and times as well as course outcomes under different deadline policies. We also compare how similar deadline policies were used by students in different courses, including first- and upper-year courses.

Unsurprisingly, more students submitted assignments late when there was no grade penalty. However, we found that many students did not take advantage of or maximize the opportunity to submit late even when given the opportunity to do so without penalty. For those who do submit late, we found a negative correlation between how late the assignment was submitted and the assignment grade for courses using grade penalty deadline policies, but not for the policies that allowed late submission without grade penalty. We also found a higher rate of individual requests for extensions outside the policy in courses using a grade penalty policy.