The simple answer to the question, "How do you stop online students cheating?" is that you don't. You discard the idea of "cheating" altogether. In days not so long past, rote learning was important because, in many professions, there was no way to access the source data within a reasonable amount of time within the arena where that information would be useful. A trip to the library in the middle of the workday was g…
That only works if you can prevent the student from simply hiring an expert to take their tests for them.