Pre/post concept assessment testing is becoming increasingly common in college courses. Instructors use different approaches to give assessments, but few studies have examined how administration differences affect results. Here, we ask if administering a posttest on the final exam differs from administering it on the last day of class with extra final exam points for scoring 100% on the posttest as an incentive. To answer this question, we compared the performance of two courses on the Genetics Concept Assessment. We find comparable results between both courses, suggesting that instructors can choose the method of administration that resonates best with their teaching style. (Contains 2 tables and 2 figures.)