"We stress-tested our university’s examination system against AI cheating in a controlled experiment,” at the School of Psychology and Clinical Language Sciences.
His team created over 30 fake psychology student accounts and used them to submit ChatGPT-4-produced answers to examination questions in five undergraduate modules, covering classes needed during all three years of study for a bachelor’s degree in psychology. The assignments were either 200-word answers to short questions or more elaborate essays, roughly 1,500 words long.
Shorter submissions were prepared simply by copy-pasting the examination questions into ChatGPT-4 along with a prompt to keep the answer under 160 words. The essays were solicited the same way, but the required word count was increased to 2,000. Setting the limits this way, Scarfe’s team could get ChatGPT-4 to produce content close enough to the required length.
Even with no editing or efforts to hide the AI usage, 94 percent of those went undetected, and nearly 84 percent got better grades (roughly half a grade better) than a randomly selected group of students who took the same exam.
“We did a series of debriefing meetings with people marking those exams and they were quite surprised,” says Scarfe. Part of the reason they were surprised was that most of those AI submissions that were detected did not end up flagged because they were too repetitive or robotic—they got flagged because they were too good.