Only allow one instance of an exam to be open at a time

[firasm]

As discussed here and brought up by Fraida Fund:

Could two students access the same exam in PrairieTest and CBTF also!? Once they’re checked in, there’s nothing stopping a second person from logging into the account of the first person and doing their test for them.

The only thing preventing a second student from doing the exam of the first student while they’re both in the CBTF is “using up” their attempt on the exam, even if it’s from a different course. The students just need to coordinate which session they sign up for.

Potential solution: Making PL only open one instance of an exam at a time?

[nwalters512]

@firasm does the introduction of client fingerprints change your request? While we wouldn't block the exam from opening on multiple machines, we do now give instructors enough information to easily tell when that happened.

I'd be hesitant to implement this because at least at the UIUC CBTF, it's very common to move students from machine to machine to deal with browser issues, hardware failures, etc. Students also sometimes log out and back into the same machine, which by any reasonable signal would be "another instance". We could of course build some elaborate system to allow proctors to override this... but again, I'm hopeful that client fingerprints solve the underlying concern here.

[firasm]

I think this is now less of a concern for me personally - instructors are now getting in the habit of scanning fingerprints as a sanity check.

But, as we add more and more courses to the CBTF, there are more and more opportunities for bad actors to get into the CBTF through "optional tests" (with no consequence or penalty to them) so I'd prefer to have a longer discussion about this issue. Knowing that someone has multiple fingerprints for an exam does nothing to help us prove that someone cheated, or who the other student might have been.