cheating on tests and assignments is also a problem that one must come to terms with. It can be very disconcerting to take up a test, and when grading them realize convincingly that some one has copied someone else or has copied something from a hidden source onto the test, especially if you noticed that person acting suspiciously during the test, but did nothing at the time.
Cheating is unusual in that usually only one or two persons in a class of 30 or so who does it, but it is often the case that there is at least one. And that one person can cause you a lot of stress.
If all you have is the fairly obvious fraudulent results after the fact, but you did nothing at the time it occurred, then you really have no proof and are in the unpleasant position of pretty much having to give a fraudulent grade to the cheater. It is depressing how often, when one sees a suspicious situation and does nothing at the time hoping it is illusory, that one does find very unlikely results on the test afterwards.
Some possible strategies include giving more than one test, to alternate rows of students so that no one can easily see the same test in anyone else's hands.
Another way I used for a long time, was to monitor the test, and simply ask anyone who looked suspicious to move to the front where cheating was not feasible. I did this very quietly and politely without giving a reason, and it worked pretty well, but is a little stressful.
Oddly enough the best solution I found was in my old age, when I became less concerned about the strictness of my grades, and I wanted to give every student the best chance possible to succeed, I simply began to help students during the test. if I saw a student glancing around, I would go back and ask if they were stuck. Usually they said yes, and then I would just help them with a hint. Sometimes I would then come up and write that hint on the board if I thought everyone should have it to be fair. This way sometimes a student points out an unclear question you need to clarify too.
Sometimes they said no. But this gave them the knowledge that I could see what they were up to, and took away the motivation to cheat, since I was willing to help them. After all my hints were worth more than a fleeting glimpse at some other paper. It seems too if they feel you are willing to help as much as you can, cheating is less likely.
I do not know how common cheating is, in some form or other. Maybe some students do not understand that using any form of assistance without acknowledging it is essentially cheating. One thing I did notice was that scores on homework, where cheating was possible, were always much higher than on tests where it was harder to cheat.
Some students complained regularly that the tests were harder than the homework, when actually the opposite was true. The problems were easier but they found them harder. The only difference was that the tests were not open book. It seems some students could benefit from learning to do homework under test conditions, or at least learn to practice for tests under test conditions beforehand.
Interestingly the best students score higher on tests than on homework, since they use the homework opportunity properly, to learn, while the desperate student uses the homework incorrectly, to pad his low score. Since the homework counted 15% and the tests counted 85%, this also showed a certain lack of grasp of the mathematics of grading.
