AI boosted homework scores, then exam scores dropped: study (economist.com)
139 points by dash2 3 days ago
GPerson 2 days ago
The kids who used AI and studied for a similar amount of time as the non-AI high performers apparently had similar (slightly higher) performance. The kids who used AI and did poorly used the AI to do the homework for them (this is what the article says).
I believe AI is basically an amplifier of bad and good. I’m cynical about the world and assume it will be used more for bad than good, but I don’t doubt some of the best people in every field will be using AI to amplify their work in good ways.
kzz102 2 hours ago
It's not so clear that AI is an amplifier.. The paper has some fascinating analysis on this topic:
"At the other end of the distribution, AI students who spend more than 65 minutes on their homework receive homework and exam scores similar to those of non-AI students, suggesting that these students do not use generative AI for homework assignments. However, this group consists entirely of students who adopted generative AI no more than Öve months. Six months after adoption, no AI student spends more than 65 minutes completing their homework (see Figure A5). This is consistent with the gradual process of learning how to use AI tools. It also suggests that AI crowds out the highest level of e§ort."
"Interestingly, in the range of 50-65 minutes, the median and the interquartile range of exam scores of AI and non-AI students are similar. This implies that, in the range where AI students and non-AI students have overlapping homework times, students who spend the same amount of time completing homework on average receive similar exam scores."
"This pattern shows that students who spend the same amount of time on homework learn similarly, with or without generative AI. In other words, generative AI reduces time spent learning for the majority of AI students but not learning efficiency for those who spend the same time studying as the non-AI students."
doctorpangloss 24 minutes ago
well most university exams are designed to measure how much you study. so we didn't really need a study to tell us, "Exams continue to measure what they are designed to measure."
they're not designed to measure general aptitude, or function as admissions criteria, or screen for job applications, or any other numerous things they are used for.
there can be many questions of pedagogy. one of them is, what do our exams measure and how do we use them? professors who say, "My exam is designed to measure who studies, not be used for all these other purposes that they are actually used for" - I don't buy it. It's the same as late night comedians saying they are not responsible for solutions, even when spending 90% of their air time making political jokes.
THIS is the pedagogical issue, that pedagogy has NEVER caught up with the scope of responsibilities. This is acute in STEM - I mean, the humanities departments are generally pretty well run, all things considered, in this regard. Generative AI is accelerating that pre-existing crisis.
nerevarthelame 2 hours ago
The scary thing is that 81% of AI users in this study were determined to be "outsourcing" their homework to the LLMs - and the rate increases the more exposure they had to LLMs.
The "slightly higher" performance is based on statistically insignificant samples (between 4 and 20 students, depending on the context, out of the total population of 26,000): https://bsky.app/profile/benjaminjriley.bsky.social/post/3mt...
moffkalast 25 minutes ago
I thought that it was generally accepted by now that homework in the volumes that it is being assigned in the modern day was not found to be beneficial in any significant way in the first place? Maybe once all students start outsourcing it to AI it might finally die like it deserves to. People these days grow up with almost no free time for themselves, it's all school, sports/extracurriculars or homework nonstop. All worker drone and no play makes for an increasingly dysfunctional society.
ambicapter 5 minutes ago
> I believe AI is basically an amplifier of bad and good.
Same can be said of technology in general tbh.
elictronic 2 hours ago
You aren’t being cynical, you’re arguing with disingenuous entities with money on the line. We already know it’s used primarily for the negative case. Everyone who ever intended High School or College knows this.
shimman 12 minutes ago
Definitely had a sheltered public school experience, took AP stats my senior year and realized all the top students were sharing answers from an earlier period through text messages. After figuring this out I too joined in on the action, then shortly after I quickly deskilled.
Suppose it's good to learn how elastic the brain is, in both directions, at a young age where it doesn't matter.
BrenBarn an hour ago
The dangerous thing about amplifying is that bad people are often more willing to amplify their activities, because they don't care about the negative effects. We are seeing this now as AI companies (and large companies of all kinds) rush to secure whatever advantages they can, regardless of the negative externalities. Meanwhile people who actually care about doing the right thing get trampled.
We need to shift the incentives by adding ruinous penalties for things that are currently quite commonplace if they are done by large players. Some dude training his own AI on his own computer can scrape and train. The fine for OpenAI or Meta using a single copyrighted book without permission should be in the tens or hundreds of millions.
What we're seeing currently in our society is a "loophole inversion" where the rules have an effect mainly via their loopholes. The most profitable activity is to find loopholes and exploit them as frenetically as possible to gain as much advantage as you can before the loophole is closed, or get people hooked on the loophole so it's retroactively legalized. Entities that are big enough to do this are big enough because they have lots of money behind them. Entities doing the same kinds of things without lots of money are not really doing much harm. So the best approach is to adopt a "sliding scale" in which even tiny violations by wealthy actors result in penalties enormously greater than fairly large violations by small players.
the_real_cher 2 days ago
This is my thoughts as well! It makes smarter people smarter and dumb people dumber!
grey-area 2 hours ago
There is zero evidence for this.
LLMs make significant mistakes frequently and smart people have no way of judging those mistakes outside their domain expertise. They are also sycophantic and great at being an echo chamber which makes people feel smart even if they are not.
So I think the burden of proof is on you to prove that they somehow amplify intelligence, it seems highly unlikely.
ndriscoll 2 hours ago
Barbing 32 minutes ago
doctorwho42 3 hours ago
All at the cost of ... {List of negatives regarding the construction and powering of AI data centers }
stevecoalbear 2 hours ago
Most importantly, it makes investors think dumb people are smart.
mrguyorama 2 hours ago
It helps smart people be barely more effective and helps dumb (more importantly, people who do not value effort, people who are lazy, people who are self absorbed) people shit out endless streams of worthless tokens that can swamp out everything.
Raising the noise floor like this only makes it that much harder to find "Smart" people, which we were already doing terrible at.
I use Claude every single day, but this is such a bad tradeoff. Maybe it will help me standup a quick fix when that is needed. Maybe it can help me dig through documentation to find relevant bits and figure out the unstated assumptions underlying it. Maybe it helps me generate test cases.
Meanwhile, my day to day life is now noise. All social media is noise. All content is noise. Slop pours onto me from all directions. Writing more test cases isn't helping me.
Am I smart? Am I dumb? I don't care, right now I'm deafened
suburban_strike 2 hours ago
altairprime 2 hours ago
wizzwizz4 an hour ago
tancop an hour ago
All AI did here is exposed an old problem in education. Kids are expected to get everything perfectly for the first time but a lot of them don't so the class gets easier next year to keep up pass rates.
We need to restructure the system to treat failure as a signal instead of a disaster. Grades should come from hard randomized exams with unlimited retakes so one bad day won't hurt you. Homework should be optional material for self study, evaluated by teachers if you choose to do it but never forced.
Hold back students for individual classes instead of a whole grade so failing one can't ruin your social life and teachers are more willing to do it. F students will realize they have to study, start actually learning and then pass on the second time. No big deal. It happened to my friends in college, no reason they can't do it in high schools.
Discipline is a skill and it's one you have to get from experience. If you try and force kids to study when they don't want to "for their own good" you're not actually helping them. Everyone needs to find their own path. Let people fail.
WalterBright an hour ago
> Homework should be optional material for self study
At Caltech, homework was assigned but had no bearing on your grade. The grades were based on the midterm and final exams.
But not mastering the homework usually resulted in flunking the exams. There were "retch" sessions after each homework assignment that was staffed by a grad student, and the purpose was to help the students understand the homework problems. I knew only one person (Hal Finney) who was so smart he didn't need to do the homework.
I learned the hard way that the path to success was:
1. never miss a lecture, no matter what
2. take notes by hand during lecture
3. do the homework on time, and make sure you understand every problem. Take advantage of the retch sessions.
And that worked for me.
WalterBright 40 minutes ago
I've given this advice many times, and the ones who followed it did well. I only added "leave your laptop in your dorm room" for modern times.
The general pattern at Caltech was 2 hours of study for every hour of lecture. Which was quite a shock to me.
eastbound 32 minutes ago
> 1. never miss a lecture, no matter what
As a student of a top-tier French Master's degree, I consulted with a teacher to deal with exhaustion and to ask for a class rescheduling for my case. Explaining my situation, the teacher looks at me and interjected:
—Waitwaitwait. You... you went to all lectures!?
And he was right. Rather than following the curriculum, I should have developed my taste for various engineering topics and only used the classes as entertainment.
doctorpangloss 29 minutes ago
do you have any evidence that CalTech's pedagogy is immune to today's threats and trends in education everywhere else? (no)
WalterBright 11 minutes ago
slaymaker1907 39 minutes ago
Unlimited retakes would be an enormous amount of work for professors/TAs/teachers.
Optional homework is often a disaster. At best, students would do it right before an exam and the goal of education is not to just pass exams. They’d probably still get a lower score than if they did the homework when they were supposed to.
What I think is better is to have a due date, but just make the maximum 10% each day it is late. So after 2 days, the highest score you could receive would be 80%.
I liked that system because it gave some flexibility with deadlines while still encouraging you to turn things in on time.
yorwba an hour ago
The study was done in China, where making the class easier to improve pass rates isn't really a thing, as the Gaokao operates more like a stack ranking where it doesn't matter much how well you did in an absolute sense, only that not too many others who did better than you are competing for the same spot. Unlimited retakes are possible in theory, except each costs you a year of your life and except for some extreme cases of repeat test-takers, most people are going to give up after just one or two bad results. Homework is definitely not optional, but going home from school is. (Due to the hukou system, children often have to go to school far from where their parents work, so boarding schools with teacher-supervised self-study are common.) I don't see how holding back for individual classes is supposed to work considering scheduling conflicts.
srveale an hour ago
> F students will realize they have to study, start actually learning and then pass on the second time
Do you have evidence for this beyond your friends (who were accepted into college)?
doctorpangloss an hour ago
> If you try and force kids to study when they don't want to "for their own good" you're not actually helping them. Everyone needs to find their own path. Let people fail.
this rhetoric is pretending to be an alternative to coercion. IMO the ideas you are talking about are well trodden and are still coercion nonetheless.
grog454 an hour ago
I could be mistaken but my interpretation is that "studying for your own good" is being contrasted with "studying so you don't fail". If you actually fail students, they'll have a second motivation beyond trusting some authority figure's advice. Namely consequences.
alightsoul an hour ago
Coercion explains it perfectly. A lot of kids see no future because of the environment they live in, so they have exactly zero motivation to study
deckar01 an hour ago
You are missing the point. Getting a certificate for all of the programs you passed and still graduating could completely change the course of a person’s life. Community college has certificates and associates degrees to let people start working when they reach a practical limit in their general education.
juleiie an hour ago
It's all cute but naively glances over what this all boils to - competition.
Education system, contrary to popular belief/name, isn't tailored to educate but to select winners and losers which then will be picked on the job market.
That's why it seems absurd when you think about it as an institution that aims to educate. That's because that isn't the real purpose of it. The purpose is to stratify and classify early.
Schools do not operate in a vacuum; they serve as credentialing gatekeepers for a hyper-competitive capitalist job market. If everyone could easily retake exams until they got an A, grades would lose their primary utility for employers and universities: differentiation. Society relies on schools to provide a neat hierarchy of candidates that for one reason or another thrived in difficult environment of adolescent schooling.
The system often prioritizes compliance, endurance of boredom, and social maneuvering over actual critical thinking precisely because those traits align with corporate hierarchies.
andsoitis 2 days ago
Moneyshot: "The results are eye-opening. After six months, pupils using ai saw their average homework score rise by 18% across all subjects. The time they took to complete each assignment fell from an average of 64 minutes to 45. But come exam time, the same students scored 20% below their classmates who had not called on ai’s help. Homework scores once predicted exam performance; now those who score highest are, perversely, more likely to do worse in exams."
Study design: "David Stromberg of Stockholm University and Victor Lei and Wu Yanhui of the University of Hong Kong set out to fill the gap. They tracked 27,000 pupils aged 12-18 in China, where ai adoption has been fast. Around 80% reported using models such as Doubao and DeepSeek; the other 20% formed the control group."
magicalhippo 2 days ago
> Homework scores once predicted exam performance
As with most training the journey is the point, not the destination.
That said, I think smart use of AI could help. It could explain concepts in a way that might help you understand better, it could probe your knowledge in a more dynamic way by tailoring questions, and so on. This requires the AI be restrained by some harness, not free to write down the answers for you.
nxc18 an hour ago
> help. It could explain concepts in a way that might help you understand better
People say that all the time, but does anyone really think a lack of good explanations for things is a limiting factor in 2026? Or even 2010?
jedberg 38 minutes ago
magicalhippo 43 minutes ago
oblio 2 hours ago
> This requires the AI be restrained by some harness
How would this magic harness look like and why would anyone use it?
jedberg 40 minutes ago
lxe an hour ago
If you structure learning in such a way that makes learning just a means to some end, and overindex on that end being the ultimate goal, that's what you get.
This is a pedagogical problem that AI merely exposed. Educators need to figure out How to make students choose the scenic route instead of having them optimize for the most efficient completion of a task.
Nevin1901 an hour ago
School has always been about creating compliant workers, not educating people. They will double down on "performing the right things" and "morals" while the economy will continue on its K shaped path as AI gets more capable.
ezst an hour ago
Could it be that you vastly overgeneralize? While there's no perfect education system, many are much better than the nightmare you describe.
mettamage 43 minutes ago
pjc50 2 days ago
Taking a forklift to the gym increases the number on the bar, but mysteriously your gains go down.
lapetitejort 2 hours ago
To extend this analogy:
Using the forklift as a spotter and to assist in loading weights increased gains. Then again, a human can do all those things, and provide real human connection.
mpalczewski 42 minutes ago
When you get out into the real world, what will matter is how effectively you use AI. When you are done with school, you can take the "exam" using AI. The problem is that teaching is trying to teach skills that are no longer relevant and is always behind what the latest going on in the industry. Every time without fail you got interns, who after two years at stanford would learn more in the 3 months on a google internship than in those two years at stanford. They learn useless shit.
My own experience is that college is fun. You can spend the time wisely, but school stuff, is not what makes you money.
Make student loans dischargeable in bankruptcy and make colleges under write them. The problem will get solved quickly.
nick486 27 minutes ago
Way before AI, the problem was very similar - universities do not teach practically useful stuff. Its been a permanent complaint about the education system, really, at least for the last 50 years.
AI just gave the students a way to dodge the slog.
But university was never intended to teach the bleeding edge. That would really be impossible in practice. Pre-phd, it is supposed to teach ways to efficiently attack a problem. you can take a bunch of "play courses", and succeeding at any of those requires pretty much only that one skill.
Nowadays, the challenge they face, is to keep teaching "problem attack methods" in a way that can't be trivialized by AI.
Though fundamentally, if you go to university, and evade learning the one thing you can learn there - thats your loss.
kermatt 2 days ago
It is stopping some of the adults I work with from learning.
In the case of some management, is causing them to unlearn, forgetting about proper review and maintenance practices.
1-6 23 minutes ago
Teachers have become proctors and not educators.
inemesitaffia an hour ago
The homework helps the teacher track their performance/progress.
When the signal is removed, this is what you get.
2716057 2 days ago
tolugenius 2 days ago
I know this study is focused in China but one thing I'd like to understand is the nuance in what kind of student is likely to always reach for ai for homework help as I think (especially in the US, can't speak for other countries) the varying powers that be that can determine the quality and type of education you can receive (does your country have means to buy textbooks per student or shared, do you have funds to give students ipads to take home or no, what sets the bar on how far curriculums can go, are teacher and faculty pay and incentives simply tied to student pass rates, etc.) and those do more in shaping what "use AI responsibly" will look like and why it's so different.
mdrzn 2 days ago
Use AI for homework, you will get it done faster and get a higher grade, and then get crushed on the exam.
jsisto 2 days ago
i’m pretty sure there’s already a correlation between technology in the classroom and worse learning outcomes
AlwaysBetOnJS an hour ago
I used to skip homework in high school because it was boring and cut into my personal life outside of school (including my job) but I would always do very well on tests.
Then I stopped caring about tests too.
I did the same thing through college. The only reason they passed me and I got a degree is that I built the school’s website and I built personal ecommerce sites for the head of art and his wife to sell their paintings.
I haven’t done shit since like 7th grade.
Worked at Facebook, Apple, Microsoft, same behavior there - did basically nothing for them while making thousands off my games on App Store.
Fuck authority