Students who use AI score great on homework, but bad on tests, large-scale new study shows

Artificial intelligence is great for school work — until you can’t use it on the test, a large-scale new study shows.

Students who used AI o write their homework got better scores and finished their work in record time —but did worse exam than kids who did things the old-fashioned way, according to new research out of China.

After six months, the students using AI saw their homework scores rise by almost one-fifth (18%) across all subjects, a joint study by David Stromberg of Stockholm University of Victor Lei and Wu Yanhui of the University of Hong Kong found.

All the while, the time they took to complete each assignment dropped from 64 minutes to 45, according to the Economist.

But when it came to exams, students who used AI for their homework scored 20% below their classmates who hadn’t, the study showed.

AI can lead to better homework scores, but worse exam results, a new study found. terovesalainen – stock.adobe.com

Experts say the rise of AI may have broken the relationship between homework grades and the amount of knowledge retained for tests.

The study tracked 27,000 students aged 12 to 18 in China, where AI adoption has been turbocharged in recent years.

Some 80% reported using Chinese AI models such as Doubao and DeepSeek, while the remaining 20% formed the control group.

Between 80 and 90% of US college students use AI in their studies. BullRun – stock.adobe.com

In the West, AI pickup has been even more drastic, with roughly 80-90% of US undergrads, 94% in Britain, and 93% in Germany admitting to using it in their studies, according to a survey last year by ed-tech firm Chegg.

But the evidence doesn’t indicate that AI is inherently a bad thing for students.

In another new study, students at Middlebury College in Vermont were taught an unfamiliar topic either with or without the help of an AI chatbot.

Those using AI scored higher on tests than the control group and had the same advantages when they repeated the task a week later, according to research by Zara Contractor and German Reyes.

“AI can boost learning productivity, but only for those who use the technology intelligently,” reported the Economist.

“Students must resist the temptation to reach for an AI-generated answer before thinking things through for themselves,” added the report.