Part of being a TA is marking. I won’t lie – this generally sucks. And I’d be shocked to find a single TA who honestly, truly, likes marking. If they say they love it, they must be lying.
Another, unfortunate, part of being a TA is catching cheaters. And I do think it’s unfortunate that this needs to be done. In a perfect world people wouldn’t cheat. But this is not a perfect world, and unfortunately there are many cheaters. Cheaters who sneak answers into an exam. Cheaters who copy others work. Cheaters who pay others to do their work for them.
In my experience, plagiarism, especially in essays, is pretty easy to catch. It just reads wrong. It’s like one person is telling you a story and then suddenly a second person interrupts to tell you a piece before the original voice takes over again. It’s perfectly fine to have other voices in an essay, but they always need be indicated by quotes. When you notice these passages, often putting a phrase in Google can quickly identify if it’s plagiarized and from where.
Catching cheaters who pay others is more difficult. And catching cheaters in beginner classes like math and programming is difficult because you expect a high level of similarity. However, there are other flags you can watch for.
If you teach a lab section, or interact a lot with the students, you will start to pick up on their strengths and weaknesses. You probably know after a few labs who’s going to sail through the course and who is going to struggle like crazy. And this knowledge allows you to notice anomalies. Like when a student gets perfect, or near perfect, on an assignment when you know their ability is no where near that level. Of course, that’s not proof of cheating, just a red flag.
Other possible red flags are students who do well on work done outside of the classroom, but their work done during class is no where near the same level/quality. Some difference can be explained by exam anxiety and pressure to complete tasks in a set amount of time. But fairly large differences are not normal.
Of course, identifying students who have cheated/are cheating is all that grad students can do. After that, the responsibility is passed on to the instructor. But if you notice something, I do think it’s a grad students responsibility to point it out to the instructor. Whether or not that instructor decides to proceed is another issue.