You know Newton’s third law? The one that says for every action in nature, there is an equal and opposite reaction? Well, the same might be said for business.

In late November, the company OpenAI launched ChatGPT, the free (at least during the current research phase) artificial intelligence-powered chatbot that has become famous — or infamous, in some circles — for its ability to quickly generate essays or any kind of writing. Now, many students are using that technology to do their homework, and school districts are seeking software to detect whether that homework has been created by AI.

One place that’s happening is Hinsdale Central High School in a suburb of Chicago. On a recent morning, students moved between classes and wished each other luck on exams. English teacher David Lange weaved around them and pointed out posters in the hallway that showcased the classics, old and new.

“‘Catch-22.’ ‘War and Peace.’ ‘Becoming’ by Michelle Obama. There’s my ‘Hamlet,’” Lange said. 

“Hamlet” — the Shakespearean tragedy — is one of the main texts Lange assigns to seniors taking his literature course. He has them write lots of essays to help them figure out what they think about the play. 

“I want students to be able to develop their own ability to make meaning of a text,” he said. 

Recently, some students at the school have delegated that thinking to artificial intelligence. Lange said that in just three days, there were at least eight instances of high schoolers cheating by submitting ChatGPT-generated writing as their own. 

“It does a good job of producing the work of a 17-year-old who is kind of phoning it in,” he said. 

This is how ChatGPT works. You go to the website, it asks if you are a robot — which, when you think about it, is pretty funny — and you can give it a prompt, like “Write an essay on themes in ‘Hamlet’ that still resonate today.”

Within seconds, text appears on the screen as if someone is typing. 

“Hamlet is driven by a desire to avenge his father’s murder, and throughout the play, he struggles with the morality of taking revenge. This theme is particularly relevant today as issues of justice and retribution continue to be debated in society.”

But no 17-year-old writes like that, Lange said. “The sixth sense of teachers who’ve been doing this for a while can see it instantly because it’s too smooth.”

The school district where Lange works, which has the official name of Hinsdale Township High School District 86, would like to deter students from doing this in the first place. It already uses software made by a company called Turnitin, which will scour the internet to see whether a student is lifting from content that’s already online. It will also compare a student’s work to papers submitted by other students.

The district said it pays $17,000 annually for Turnitin, and it would be willing to buy a new product that will catch text generated by AI. (The company said its prices vary depending on several factors, including district enrollment.) 

“It’d be another tool for the teachers to use to determine the writing style and if it’s something that is just copy and pasted off of ChatGPT,” said Keith Bockwoldt, chief information officer for the district. 

Lots of other districts, as well as colleges, are asking Turnitin for this kind of tool.

“We are getting an influx, a huge influx of customers who are saying, ‘We need help, we’re not sure what to do,’” said Patti West-Smith, senior director of customer engagement for Turnitin. 

West-Smith added that prior to the launch of ChatGPT, Turnitin had already been developing software that can tell whether a piece of writing relies on AI and to what degree. Now, it is frantically working to release that product this year. 

“Which is why probably the first version of this that comes out will not be the prettiest thing we’ve ever produced,” West-Smith said. 

At least one free app is already out. Princeton senior Edward Tian created GPTZero, which he said can detect how random human writing tends to be.

“Humans are like, ‘Oh, suddenly, I have this thought.’ And then, ‘Oh, actually, suddenly, I have this thought.’ And that causes some differences,” Tian said.

“Never trust anything that can think for itself if you can’t see where it keeps its brain.”

— Mr. Weasley, “Harry Potter and the Chamber of Secrets,” by J. K. Rowling

Tian has already received interest from venture capitalists, he said, though he doesn’t have plans to take investments right now. 

Potential customers for this kind of software go beyond high schools to include colleges and workplaces.

“I can imagine any industry in which the originality of the work matters. I mean, journalism could potentially be an example of this,” said Kelly Calhoun Williams, a research vice president analyst for Gartner.

OpenAI, the company behind ChatGPT, said in a statement that it doesn’t want the app to be used for “misleading purposes in schools or anywhere else.” It said it’s already developing mitigations to help users identify text generated by the system.

Plus, ChatGPT has its own limits. OpenAI warns it will occasionally “make up facts” or “hallucinate” answers. It also doesn’t tell you how it knows something.

Which calls to mind a line from a “Harry Potter” novel: “Never trust anything that can think for itself if you can’t see where it keeps its brain.” (Thanks, Mr. Weasley.) 

Educators say they have to learn to work with AI, just as they had to learn to work with other disruptions, like Google. 

“OK, there’s this thing that can do some pretty cool things, and it’s a tool,” said Kim Williams, and English teacher at Hinsdale Central High. “So I think using the tool is something we’re going to have to adapt to in teaching.”

Williams said she’s thinking about what she’ll need to teach students to use ChatGPT ethically. “We’ve been doing a lot of thinking about how will this change instruction, not just to catch cheaters, but there’s new technology in front of us, and it’s only going to get better.”

Because her job is teaching kids how to use their brains, and in the future, those kids will need to work with all kinds of software — even software that can’t show us theirs.