When Greg Kestin was a graduate student back in 2017, he worked on PBS’ signature science program NOVA, exploring how artificial intelligence might reshape the world.
“I was already thinking of the replacement of a person,” he recalled while sitting in a Harvard physics lab where he now teaches.
Last year, Kestin put that idea of replicating a human being into practice. He built a platform called TeachGPT, a custom chatbot that serves as an always-on tutor that mimics himself.
“I never am intending to replace anyone, but sort of take some of the more rote aspects of teaching and let the AI do that,” he said. “I’m using AI as a tool that’s informed by the way that I would teach.”
Study after study show most college students are using generative AI to help juggle everything on their plates, from brainstorming ideas and study prep to keeping up with emails. At Middlebury College, more than 80% of students who were surveyed recently said they use generative AI, though only about one-third of surveyed students said they use it frequently.
Critics say these new tools are eroding students’ communication and critical thinking skills and undermining education and the academic enterprise. But students and professors like Kestin argue AI can actually enhance learning, not cheapen it.
Instead of a generic chatbot app fueled by the entirety of the internet, Kestin and his colleagues built TeachGPT to be focused on specific courses and pre-vetted material from those professors. Students who use the app can find video lectures and practice quizzes alongside the chatbot tutor, offering a guide — but not always the direct answers — to support their learning.
Two of Kestin’s students, seniors Arezoo Ghazagh and Nayan Sapers, say TeachGPT has helped them grasp the basics of physics.
“It’s specifically made by our course staff, so we know that anything that’s going to be spitting back at us is something that our professor is going to see and has been reviewed before,” said Ghazagh, a neuroscience major.
“It made me be able to be a lot more engaged in class. I would come in already with a pretty strong conception of that day’s material,” added Sapers, who studies biology and psychology.
Kestin measured the performance of his AI tutor in a controlled group study and found students who used TeachGPT learned basic concepts better — and faster — than they could in class.
“Students could learn more, and also felt more engaged and motivated,” he said.
Katie Shilton, a tech ethics professor at the University of Maryland in College Park, sees opportunity for the rest of higher education.
“Individualized tutoring is a really exciting potential use of these technologies,” she said.
In her own classes, Shilton knows AI isn’t going away, so she asks students to use it in ways that align with their values and goals. AI tutors, she said, can give them the freedom to ask questions they might be embarrassed to ask “because they don’t want to seem like they don’t know, or just really regular student reasons.”
And, Shilton added, this new technology is scalable. High schools, community colleges, big universities — they all could plug in.
Even with the technological advancements, Shilton doesn’t predict professors will be replaced anytime soon.
“I don’t see it,” she said. “There’s much more that goes on in a classroom besides tutoring and information being fed at you from a screen. Those things are not replaceable in the ways that chatbots work right now.”
Kestin agrees. He’s now collaborating with Harvard’s math department as well as colleagues at Yale and Stanford on more custom-made tutors. Even some local high schools are interested in using something other than an “off-the-shelf” chatbot.
Still, Kestin said schools will have to tread carefully into this brave new world.
“I don’t encourage anyone to just put a chatbot in the classroom,” he said, noting how students can circumvent their critical thinking. “They do just get to the end result rather than thinking through it.”
His advice to teachers out there? AI tutors should never replace — only enhance — human interaction.
