Most common ways of cheating on exams? I've been thinking how I proctor and design exams, and I suspect (from things I hear) that there is much more cheating than I find evidence of.  What are the most common ways university students cheat, say in a large lecture math or science class?  For instance, some possible ways are:


looking at other students exams
sneaking in a cheat sheet
using a phone/prohibited device in class
getting help on a bathroom break
having someone else take the exam for you
getting a copy of the exam in advance
modifying an exam after grading and asking for points back


But I don't know if any of these happen often enough that I should do more than I currently do.

Ideally, I'd like an answer with data from some studies on cheating, but I'd welcome extensive ancedotal evidence as well.
The most common issue I observed is looking at other students' exams. A student who has a particularly good eyesight sits behind a second 1-alpha student and copies from the sheets of the latter student.

You forgot several variations on the topics you've mentioned, such as hacking to


obtain the exam in advance
modifying the exam in advance
modifying the student's answers a posteriori.


We see attempts of such actions, and we have no idea of how many such attempts have been successful. It can be anything between 0% and 99%.
Another common thing we see are attempts to bribe the teaching assistants. It does happen, although rarely.