38 students took an exam that pulled 5 questions randomly from 5 different categories with ~40 questions in each category. 2 students received the same exact exam. They started it and ended it at the same time, missed the same questions, and received the same score. They were sitting close together in the same room.
How is this possible? This is on version 2.5.1
Thanks
A naive calculation might suggest that the odds of this happening by chance were 1 in about 100 million (405). That would be the case if the numbers truly were random.
However, computers can only generate pseudo-random numbers, normally starting from some sort of seed. Is there some way this could be exploited so two students get the same random selections? I can't see anything in the code that would allow that, but I might be missing something. Also there is currently a very technical discussion going on in MDL-41198 about how Moodle seeds the random number generator in certain places - but I don't think they would affect the quiz.
Can I ask if your Moodle server is running Windows or Linux?
Tim,
We use Linux. Is there something anything I could be checking to see if the system was exploited? If I knew the right questions to ask I could provide information to our server support team.
Barbara
