From the article…

A week before the test, I told my class that the Game Theory exam would be insanely hard—far harder than any that had established my rep as a hard prof. But as recompense, for this one time only, students could cheat. They could bring and use anything or anyone they liked, including animal behavior experts. (Richard Dawkins in town? Bring him!) They could surf the Web. They could talk to each other or call friends who’d taken the course before. They could offer me bribes. (I wouldn’t take them, but neither would I report it to the dean.) Only violations of state or federal criminal law such as kidnapping my dog, blackmail, or threats of violence were out of bounds.

Gasps filled the room. The students sputtered. They fretted. This must be a joke. I couldn’t possibly mean it. What, they asked, is the catch?

“None,” I replied. “You are UCLA students. The brightest of the bright. Let’s see what you can accomplish when you have no restrictions and the only thing that matters is getting the best answer possible.”

http://www.popsci.com/science/article/2013-04/why-i-let-my-students-cheat-their-game-theory-exam