But there is an inconvenient catch. In a field experiment involving nearly a thousand high school students solving math problems, access to GPT-4 raised their practical assignment grades by 48% in the version replicating the standard ChatGPT interface and by 127% in the version with protective hints. And when access was removed, students in the first group performed 17% worse than those who had not used AI at all. The assistant worked like a crutch: while