A researcher behind StudentBench says a July–September 2026 study involving 2,383 students found AI tutoring as good as expert human tutoring for immediate GRE learning gains. Students took tests before and after an hour with an AI tutor, a human tutor or no tutor; learning gains were measured by score changes, without LLM judges. The researcher also cites a 140-student comparison claiming equivalent learning at $75 per hour for a human expert versus 7 cents for AI. They say the top AI tutor beat expert human tutors on average in five of seven academic topics. According to the announcement, all study data was released free on Hugging Face, and StudentBench's website is free to use.