
How to deal the this situation when it comes up?
I am dealing with it currently, so I called the students into my office individually to listen to the explination of the situation and talked to the instructor of the course and looked at the quiz outcomes of both students who were accused and compared answers. Then discussed findings with students and teacher and also the accuser. I discussed the appearance and behavior that is expected during tests and quizzes and to avoid any appearance of possible cheating behavior.
I separate students by at least one seat when they take tests. It can also help to create two versions of a test and distribute these tests so that each student is flanked by two people who are taking a different test version. To make it easier on yourself and fair for all the students, use the same questions on both versions, but put them in a different order.
Before every test, I rearrange my classroom, to give the students more room, and allow them to select any seat available. I remind them that if they appear to be cheating, that they will be asked to turn their test in immediately. This usually prevents a large amount of gazing. Sometimes what appears to be cheating is really them searching through their mind for an answer.