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Harvard’s new computer science teacher is a chatbot

independent.co.uk

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Re: Harvard’s new computer science teacher is a chatbot

#31
post #22

CS50 was a gigantic intro class designed to whet non-comp-sci students appetite for coding and computer science, generally. (I took it when it was C/PHP, so they may have changed things.) While the lectures are very straightforward, the smaller 'sections' lectures with the dozen-or-so teaching fellows were more intensive, and p-sets were pretty challenging for newbies. The weekly help sessions ended up being a millio…

I find it hard to reconcile "The weekly help sessions ended up being a million lost students in a giant hall waiting to see one of a few dozen TAs offering uneven pedagogical quality." with "very, very well-funded class". Why didn't the funding go to hiring more staff? My experience in a state school had far more access to education staff than what you describe, and for less funding.

Feom what I understand of these universities with endowments they use money to hire administrative staff and to "last forever". Teaching staff is secondary to those.

Re: Harvard’s new computer science teacher is a chatbot

#32

CS50 was a gigantic intro class designed to whet non-comp-sci students appetite for coding and computer science, generally. (I took it when it was C/PHP, so they may have changed things.) While the lectures are very straightforward, the smaller 'sections' lectures with the dozen-or-so teaching fellows were more intensive, and p-sets were pretty challenging for newbies. The weekly help sessions ended up being a millio…

> The weekly help sessions ended up being a million lost students in a giant hall waiting to see one of a few dozen TAs offering uneven pedagogical quality. The assignments were often automatically graded upon submission and you often have some equivalent of a unit test to see if you got it right before submission, so you know if you got it wrong, but not how wrong. Just having a resource for sanity checks and walkthroughs of lesson concepts without trudging to the hall-o-TAs is prolly really useful.

It's been a while since I was an undergrad, and I didn't study CS when I was (I was in math -- we didn't even get the unit test to tell us we were wrong lol). I understand auto-grading like this is very common in lower level CS classes, but wouldn't it be possible to write these "test suites" in such a way that they could provide some hints on exactly what was wrong? I have to imagine, based on my experience as a graduate TA in math, that undergrads as a whole make mistakes that typically fall into certain classes, and that those classes could be reflected or captured in the pattern of which "unit tests" end up failing. It doesn't strike me as terribly difficult to analyze these patterns of failures, after running the course at least once, and come up with useful hints as feedback.

Does nobody do this? Or, perhaps more to the point, does nobody ask their TAs to do this?

> Totally legit philosophical debates aside, I think this is a great use of the technology. It's a very, very well-funded class (bigger dedicated full-time year-round staff than some entire departments,) so I'm sure it's not a half-assed effort.

I agree broadly with this. If you're going to do this experiment, in principle, a class like Harvard CS-50 sounds like the right place to start, for the reasons you've listed.

However, if this chatbot is just an equivalent of ChatGPT with the GPT-4 model and some additional training/fine tuning, I don't think the technology is quite there yet. We've seen a lot of examples already of how GPT-x has a tendency to give "confidently incorrect" answers, and that's the absolute last thing you want to be telling beginners. I've seen answers that could plausibly fool experts, yet be wrong enough as to be useless once you try to verify the details. The danger here is that beginners may not recognize this, and may not be able to verify the details.

That said, I think there is a future for this sort of technology in precisely this type of instructional environment. The "confidently incorrect" problem is something that can be mitigated with fine-tuning, proper prompt engineering, and other techniques, but, to my knowledge, can't be eliminated if the system is essentially a bare text interface into an LLM. I think the work being done with web search is a possible direction here, since I've seen GPT-4 essentially give up and go search the web when pressed for details or when the actual answer would become too complex. For a restricted domain like CS50, maybe even some kind of formally encoded knowledge base would help it (similar to how I mentioned analyzing patterns of failures to provided hints).

What I do know is that the gigantic "hall-o-TAs" is absolutely not a great user experience for undergrad learners, so anything that offers the potential for improvement on that UX is definitely something I'd like to see pursued and developed.

Re: Harvard’s new computer science teacher is a chatbot

#34

"Our own hope is that, through AI, we can eventually approximate a 1:1 teacher:student ratio for every student in CS50" Would this not be a 0:1 ratio? Not against LLM's for some coding assistance, I use it daily. , but equating a teacher with an LLM solution feels like calling a youtube video a 1 on 1 tutoring session. Well at least a semester at Harvard isn't costing you much ...

I would say that an LLM could count as a "teacher" of sorts, so it would be more than a 0:1 ratio. But, if we're comparing LLM-teacher to human-teacher, I don't think it reaches full 1:1. I dunno, I'd say maybe 0.5:1 or 0.25:1 would be more accurate, given that the thing doesn't even produce correct information a certain percentage of the time?

Based on my experience with ChatGPT, it does really well as a "rubber duck." [0] Sometimes, it even gives back useful suggestions. Sometimes, it's just so far off base, I wonder what planet it's getting its advice from.

If I were the professor in this case, I think I'd suggest that students use it as a supplement: try LLM-TA first, look into its suggestions, and if it helps, great! If not, then try a few more things, maybe consulting LLM-TA a few more times. If that doesn't get you to working code and an understanding of the problem, then try human-TA. I think this represents something close to the optimal workflow for this tool, given the known limitations of the underlying technology.

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[0]: https://en.wikipedia.org/wiki/Rubber_duck_debugging

Re: Harvard’s new computer science teacher is a chatbot

#35
post #7

I assume that the savings will be passed on to students?

We're considering doing something similar in my department. Based on some back-of-a-napkin math, it won't (yet) be cheap though, at about $0.40 per query. This is assuming the use of gpt-4 (chatgpt would be a lot cheaper, but it doesn't follow system level instructions very consistently, often spilling answers instead of replying with feedback, hints and leading questions). Also, projected costs per query are high be…

Could you possibly reduce those costs by fine-tuning the model with the assignment text and reference code, rather than including them in the prompt?

Re: Harvard’s new computer science teacher is a chatbot

#36

Professor Malan said students would be warned of the pitfalls of the AI, saying they should “always think critically” when presented with information. I want to believe that this will actually happen, but my experience with people blindly trusting what a tool (not even an AI-based one) says, including but not limited to students, suggests that's not going to happen.

"Always think critically"? "Simply read the textbook" would be a more practical instruction, and also what I did in university anyway. Critical thinking is a useful description but not a good prescription. It's like telling someone to always be orange. If you want that to happen you have to eat carrots. It won't just happen by fiat or willpower.

Youtube + textbook + good discord (slack or IRC etc.) can replace an undergrad CS course pretty well IMO for at least the practical skills. AI can help but is a minor piece, at least right now.

Re: Harvard’s new computer science teacher is a chatbot

#39
post #28

Professor Malan said students would be warned of the pitfalls of the AI, saying they should “always think critically” when presented with information. I want to believe that this will actually happen, but my experience with people blindly trusting what a tool (not even an AI-based one) says, including but not limited to students, suggests that's not going to happen.

“Always think critically” is poised to become the “drink responsibly” of AI. A convenient and counterproductive way to push responsibility onto the users. https://en.wikipedia.org/wiki/Alcohol_advertising#Drink_resp... https://youtube.com/watch?v=DnSp2S7vzH4&t=31s

Agreed, and due to the way LLM works, misinformation tends to look very plausible.
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