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Comment by aidenn0 | Hacker News Reader

Anybody know how many students take CS 10 in a typical spring semester?

I believe it’s still a single section, so probably around 250 (at least that’s about what it was when I was there a long time ago). Compared to the 1000+ who take 61A.

So that's more than 10%, and (assuming the reporting is accurate) this was on an exam, not homework...

Or how many are normally caught cheating?

Did they use AI to detect AI using cheaters?

And if cheating was triggered using AI detectors, was it real?

AI detectors are pretty mid in practice - they tend to have a lot of false positives for "B" students who are okay, but can still be struggled to be more coherent than AIs are. There are some specific triggers that AIs are way more likely to do than students, but a lot of AI detectors will trigger on this "almost there, but you're still struggling" level of essay writing that might get a B, B-.

I could expect the same might be true for CS students even though I haven't seen how AI detectors work for CS/math homework.

You'd be amazed at how many students we know are obviously cheating because the logs reveal that they copy pasted a long, complete answer within seconds of opening a problem for the first time, full of sophisticated code constructs that we didn't teach them, and lot's of nicely formatted comments. Sometimes they even copy/paste the entire GPT output and then format it down.

This has been my wife’s experience as a college math professor. Instead of code it’s extremely formal problems with way more steps than the student normally performs using notation never taught in class.

It’s not that students didn’t cheat before, LLMs have just lowered the bar so far many can’t complete a live test in a class that requires effort.

Public schools around me have done more than just turn a blind-eye to cheating. During COVID, one of our kids cheated in every subject, we showed the proof to the school and only one of the teachers had any consequence at all, and that was to give her a failing grade for the test we could prove she cheated on (quizzes and HW were ignored).

It was trivial to show she had plagiarized every single essay she wrote (just put any unusual sounding sentence in google with double quotes around it), and her English teacher said roughly: "Yeah, lots of kids are doing that these days, nothing we can do about it"

When I was a section leader (not at Berkeley, though) we used MOSS: https://theory.stanford.edu/~aiken/moss/

It's not AI, its a deterministic program that analyzes compiled code for similarity.

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