Comment by xdennis

> I teach CS, and oh we know but I don't know what to do about it.

You could give students larger projects and have them present their homework.

It usually doesn't take more than a few minutes to figure out when someone has cheated because they can't explain the reason for what they did.

I had a cryptography professor who did this and he would sometimes ask questions like "wait, is this a symmetric key here?" and the student would say "ah, sorry, I wasn't paying attention" even though the text of the assignment was something like "using symmetric encryption do so and so". Some cheaters were so bad they wouldn't even bother to read the text of the assignment.

Also, people who cheat tend to equivocate when asked questions. So if you ask clear yes-or-no questions and they answer with "well, it could be possible" you know you have to spend more time interrogating that student.

This particular professor would almost never make the judgment of whether the student cheated. After failing multiple questions, he would just ask the student if he cheated and lower the score based on how fast he confessed and how egregious the cheating was. Most cheaters would fold quite quick, but some took longer.