Above the Law has a post about various law professors who recently got into trouble by reusing questions from past exams. When some of their students got hold of the previous exams and used them to study for the new one that included some of the same questions, all sorts of difficult issues arose. For example, how should the new exam be graded? If the professor follows his original grading system, those students who had access to the old exams will have an unfair advantage. But excluding the repeated questions also creates problems, for example by failing to incorporate into the grade students’ knowledge of the material covered by those questions. A more equitable approach might be to make everyone take a new version of the exam. But that of course creates lots of extra work for both the students and the professor, and forces innocent students to pay the price for the professor’s mistake.
Without passing judgment on the details of these particular cases, I think it’s pretty clear that reusing exam questions is a bad idea in this day and age. Even if the professor or the law school administration takes precautions to keep old exams secret, it’s too easy for copies of the exam or details of the questions to leak out. And in the age of the internet, once they do leak out, there’s a good chance that someone will post the information online.
Thus, the safer bet is to develop new questions each time. I actually go further than that and make past exams and answer keys freely available to students on the class website. That way, no one can complain that some students got an unfair advantage over others by finding a copy of one of my old exams somewhere on the internet. In addition, access to past exams helps students know what to expect and may help them learn the material.