Prisoner's dilemma, exam grading, and social media

Long long ago I wrote an undergraduate exam that included a prisoner's dilemma question framed as the question of whether to study or not for a particular exam, with your payoff on the exam depending in part on what other people did.  Here is that story brought to life, complete with how it was organized by social media, and enforced by a contingent strategy that depended on mutual observation. (The url is more informative than the headline:

http://www.insidehighered.com/news/2013/02/12/students-boycott-final-challenge-professors-grading-policy-and-get


"Since he started teaching at Johns Hopkins University in 2005, Professor Peter Fröhlich has maintained a grading curve in which each class’s highest grade on the final counts as an A, with all other scores adjusted accordingly. So if a midterm is worth 40 points, and the highest actual score is 36 points, "that person gets 100 percent and everybody else gets a percentage relative to it,” said Fröhlich.

"This approach, Fröhlich said, is the "most predictable and consistent way" of comparing students' work to their peers', and it worked well.

"At least it did until the end of the fall term at Hopkins, that is.

"As the semester ended in December, students in Fröhlich’s "Intermediate Programming", "Computer Science Fundamentals," and "Introduction to Programming for Scientists and Engineers" classes decided to test the limits of the policy, and collectively planned to boycott the final. Because they all did, a zero was the highest score in each of the three classes, which, by the rules of Fröhlich’s curve, meant every student received an A.

“The students refused to come into the room and take the exam, so we sat there for a while: me on the inside, they on the outside,” Fröhlich said. “After about 20-30 minutes I would give up.... Then we all left.” The students waited outside the rooms to make sure that others honored the boycott, and were poised to go in if someone had. No one did, though.

"Andrew Kelly, a student in Fröhlich’s Introduction to Programming class who was one of the boycott’s key organizers, explained the logic of the students' decision via e-mail: "Handing out 0's to your classmates will not improve your performance in this course," Kelly said.
"So if you can walk in with 100 percent confidence of answering every question correctly, then your payoff would be the same for either decision. Just consider the impact on your other exam performances if you studied for [the final] at the level required to guarantee yourself 100. Otherwise, it's best to work with your colleagues to ensure a 100 for all and a very pleasant start to the holidays."

"Kelly said the boycott was made possible through a variety of technological and social media tools. Students used a spreadsheet on Google Drive to keep track of who had agreed to the boycott, for instance. And social networks were key to "get 100 percent confidence that you have 100 percent of the people on board" in a big class.

"Fröhlich took a surprisingly philosophical view of his students' machinations, crediting their collaborative spirit. "The students learned that by coming together, they can achieve something that individually they could never have done," he said via e-mail. “At a school that is known (perhaps unjustly) for competitiveness I didn't expect that reaching such an agreement was possible.”
Although Fröhlich conceded that he did not include such a “loophole” in the policy “with the goal of students exploiting it,” he decided to honor it after the boycott.

"Despite awarding As to all the students who participated in the boycott, the experience has led Fröhlich to alter his long-held grading policy.
“I have changed my grading scheme to include ‘everybody has 0 points means that everybody gets 0 percent,’ ” Fröhlich said,  “and I also added a clause stating that I reserve the right to give everybody 0 percent if I get the impression that the students are trying to ‘game’  the system again.”