AI Boosted Homework Scores by 18% – Then Exam Scores Dropped 20%, Study Shows

# AI Boosted Homework Scores by 18% — Then Exam Scores Dropped 20%, Study Shows Source: [https://canews24.online/?p=71](https://canews24.online/?p=71) 7,875 A new study tracking 27,000 students in China has found that pupils who used artificial intelligence tools saw higher homework scores over time, but performed worse than their peers on exams taken without AI assistance, according to research covered by The Economist on August 18\. ## The Study The research was conducted by David Stromberg of Stockholm University along with Victor Lei and Wu Yanhui of the University of Hong Kong\. The study followed 27,000 pupils aged 12 to 18 in China, where adoption of AI tools among students has grown quickly\. Around 80% of the students surveyed reported using AI models such as Doubao and DeepSeek, while the remaining 20%, who did not use such tools, formed a control group\. According to figures shared by The Economist, students who used AI saw their average homework scores rise by 18% across all subjects over a six\-month period\. However, when the same students were tested under exam conditions without access to AI tools, they scored 20% below classmates who had not used AI during the study period\. ## Context on AI Adoption Among Students The study cited broader data on how widespread AI use has become among students\. A survey conducted last year by ed\-tech firm Chegg found that 80% of undergraduate students in wealthy countries reported using AI in their studies\. More recent polling put the figure at 94% among students in Britain and 93% in Germany\. The Economist noted that teachers have reported grading formulaic, similar\-sounding essays they suspect were generated by AI chatbots such as ChatGPT, but said that, prior to this study, robust evidence on AI’s actual effects on learning outcomes had been limited\. ## Related Research A separate study conducted in 2024 at the University of Pennsylvania examined a similar dynamic on a smaller scale\. Students attending a math lesson practiced problems using either traditional study methods, such as notes and textbooks, or AI tools including ChatGPT and an AI tutoring program\. According to a summary of the research, students using AI performed better during short\-term practice sessions, but the advantage did not carry over to a subsequent closed\-book test\. ## Reactions The Economist’s summary of the findings, shared on the social platform X, drew significant engagement, with some commenters attributing the exam score gap to students copying AI\-generated answers without engaging deeply with the material\. The study was also discussed on forums including Hacker News, where some users questioned aspects of the study’s design while others noted it aligned with existing concerns among educators\. A tip sheet published by the Brookings Institution earlier this year said AI can support learning when used intentionally and designed well, but cautioned that overreliance on the technology to replace thinking, social interaction, or creativity could prevent students from developing cognitive and social skills\. The Stockholm University and University of Hong Kong researchers’ full study had not been independently verified by other institutions at the time of publication\.