The study you should know about
In 2024, researchers ran something close to the experiment every student privately wonders about. Bastani and colleagues worked with roughly a thousand high school students in Turkey, across grades 9 to 11, in maths.
Students were split three ways for their practice sessions:
- Control — practice as normal, no AI.
- GPT Base — a standard GPT-4 chat assistant. Ask anything, get an answer.
- GPT Tutor — the same underlying model, but constrained: it gave hints, asked questions, and would not hand over the solution.
During practice, both AI groups did better than the control group. Not slightly better. GPT Base students got about 48% more practice problems right. GPT Tutor students got about 127% more right. If you stopped the study there, you would write a press release.
Then came an exam. Closed. No AI for anyone.
The GPT Base students scored about 17% worse than students who had never had the tool at all. The GPT Tutor students came out roughly level with the control group — the safeguards removed the harm, though they did not produce a lasting gain either.
Read that carefully, because the obvious reading is wrong
The intuitive story is "the AI group was lazy." That is not what happened. The AI group *worked and performed better* during practice. They were not doing less. They were doing something else.
The intuitive story two is "AI is bad for learning." That is not what happened either — the two arms used the same model. The variable that moved the exam score was not whether AI was present. It was whether it gave answers or gave hints.
That is a much more useful finding, because it is something you control. You cannot change what model your school has access to. You can change what you ask it for.
Why practice performance and learning came apart
This is not a strange new effect of AI. It is a well-documented feature of how memory works, and it has a name: desirable difficulties, from Robert Bjork's work in the 1990s.
The short version: the conditions that make performance *during* study feel good and look good are frequently the conditions that produce the least durable learning. Conditions that feel slow and error-strewn — recalling from memory, spacing sessions out, mixing topics — feel worse and work better.
An AI that answers is a machine for making study feel good. Every step arrives clean. You never sit in the gap. And the sitting in the gap, it turns out, was not an obstacle to the learning. It was the learning.
There is a related result worth knowing: Roediger and Karpicke (2006) had students either reread a passage repeatedly or read it once and then try to recall it. Five minutes later, the rereaders won. A week later, the recall group remembered substantially more — and, notably, the rereaders had *predicted* they would do better. The feeling of readiness pointed the wrong way.
What is not settled
Be honest about the state of the evidence, because you will meet people who overclaim in both directions.
The Turkey study is one study. One subject, one country, one model version, one age group. Maths is unusually well-suited to the design; nobody has shown the same numbers for essay writing or lab work. A 17% drop is large, and single large effects sometimes shrink when repeated.
A widely shared 2025 MIT Media Lab preprint ("Your Brain on ChatGPT") reported weaker EEG connectivity in essay-writers using an LLM, and that most of that group could not quote a sentence from an essay they had finished minutes earlier. It is suggestive. It is also 54 participants and, at release, not peer-reviewed. Do not treat brain scans as proof of anything about your degree.
What is solid is the underlying mechanism, and it has forty years behind it: you remember what you generate, not what you read. The Turkey study is a clean demonstration of that principle meeting a new tool.
The practical conclusion
You do not have to give up the tool. You have to change what you ask it to be.
Every time you are about to type a question, you are choosing between GPT Base and GPT Tutor. The model does not choose. You do, in the prompt. The next lesson is about how.
Before you move on