AI boosts homework scores but harms exam performance, large study finds

A six-month investigation of 27,000 Chinese students aged 12 to 18 revealed that AI-assisted homework led to an 18% increase in assignment scores and cut average completion time from 64 to 45 minutes. Despite these gains, exam results for the AI group fell 20% below those of classmates who completed work without AI. The researchers, including David Stromberg of Stockholm University and Victor Lei and Wu Yanhui of the University of Hong Kong, attribute the gap to a possible disruption of knowledge retention.

The study noted that about 80% of participants used Chinese AI models such as Doubao and DeepSeek. In contrast, a separate experiment at Middlebury College in Vermont found that AI-aided learning improved test outcomes for students there. Experts caution that AI can enhance productivity when used thoughtfully, but students should avoid relying on AI answers without critical thinking.