You hand in an essay. A week later you get a grade and some neat, detailed feedback. A teacher read it — probably. But AI essay grading is now one of the most common ways schools use artificial intelligence, and most students, parents and even teachers do not know how well it really works.
Here is the short answer from the research so far. AI gives the same kind of grade every time. That is not the same as giving the right grade. The gap between those two things is where marks get lost.
Do teachers actually use AI to grade essays?
Yes, and it is common now. A Gallup survey of 2,232 US public school teachers, done in spring 2025, found that six in ten teachers had used an AI tool for work that year. Three in ten used one every week. Marking and feedback is one of the first jobs they hand to it.
Teachers are not being lazy. The same Gallup research found regular AI users saved about 5.9 hours a week. Over a school year that adds up to roughly six weeks. Marking a full class set of essays takes longer than almost anything else a teacher does, so it was always going to be first in line.
Of the teachers who used AI for marking and feedback, 57% said the feedback got better. That is a real finding, and it matters. AI feedback is often longer and faster than what a tired teacher can write at 11pm on a Sunday. But long and fast is not the same as correct.
How accurate is AI essay grading?
It is roughly right, and wrong in a pattern. When researchers compare AI marking to expert human markers, the AI usually lands close to the human average score for a whole class. But it often disagrees with the human on any single essay. It pushes most grades toward the middle, and it struggles most with the essays that sit in the middle.
A few findings are worth knowing:
- A study comparing ChatGPT and human graders found GPT-4 matched the human average score closely, but leaned heavily toward middle grades and often disagreed with human markers on individual papers.
- When AI was tested against official IELTS English exam markers, it was steadier than the humans but only moderately close to the official scores.
- Research on short-answer marking found the AI agrees with experts most on clearly excellent and clearly poor answers, and least on everything in between.
- In one study of essays in a psychology course, the teachers and the AI barely agreed at all, and the AI marked more generously.
Put simply: AI essay grading can tell brilliant from terrible. It is much weaker at the B-versus-C calls, and those calls make up most of a report card.
Where AI grading goes wrong
The mistakes follow a few clear patterns.
It pulls everything toward average. Unusual essays get dragged back to the middle. Reporters covering AI marking in California schools quoted a high school English teacher who noticed her tool sometimes gave her best students lower grades than they deserved. An original argument looks impressive to a person. To a model, it just looks different from the usual answer.
It rewards neat writing over good thinking. AI is good at spotting surface things — clear structure, linking words, a wide vocabulary, varied sentences. A tidy essay that says nothing can score well. A messy essay with a genuinely smart idea can score badly.
It can be unfair to some students. Studies of automatic essay marking have found the scores can shift depending on whether English is the student’s first language, and on the student’s race or family income. A student writing in their second language may lose marks for wording that a human marker would have read past.
Nobody checks the machine. This is the real problem. When a teacher reads AI feedback, there is a known habit of trusting the machine simply because it sounds confident. A grade that arrives already written, with reasons attached, is much harder to argue with than an empty box.
What are the rules on AI grading in schools?
Mostly, there are none. That gap should worry parents more than the technology does. AI essay grading spread through classrooms faster than any rules about it, so in most schools nobody has to tell you a machine was involved.
A 2026 Gallup survey run with the RAND American Teacher Panel found nearly 60% of teachers had been given no guidance at all on using AI to mark work or write feedback. A separate survey of 303 teachers in Wisconsin and 132 school staff across the US, run over spring 2025 and 2026, found only about a third of school districts had any written AI policy.
Now compare that with the student side. About 84% of high school students said they used AI for schoolwork in 2025, according to College Board figures. Schools moved fast on that, with detection software, honour codes and disciplinary hearings.
The double standard students have noticed
A student who uses AI to help write an essay can be called to a misconduct hearing. A teacher who uses AI to mark that same essay usually faces nothing, because no rule exists. Students have spotted this, and it damages trust in marking more than any single wrong grade would.
To be fair, the problem runs both ways. AI detection tools are unreliable too, and being accused because of one is its own headache. We looked at what actually proves AI use in Falsely Accused of Using AI? What Actually Proves It. The same trap applies to marking: a confident machine answer gets treated as proof, when it is only a guess.
Something similar happens in hiring, where the fear of being rejected by a robot is bigger than the reality. If that interests you, see Does AI Really Reject Your CV Before a Human Sees It?
What to do if you think AI graded your work
If a grade feels wrong and the feedback reads oddly generic, you have more room to push back than you think. Some practical steps:
- Just ask, politely. “Was any AI tool used to mark this?” is a fair question, not an accusation. Most teachers will tell you straight.
- Look for the signs. AI feedback tends to be long, built the same way for every student, full of general advice like “add more supporting evidence”, and thin on any mention of the actual sentences you wrote.
- Ask for a human re-read, not a re-grade. Point to something specific: “I think the argument in paragraph three was missed.” That is much harder to turn down than a general complaint.
- Check the school’s policy. Many districts have published AI rules in the last two years. Yours may already require the school to tell you.
- Parents: ask the school, not the teacher. Whether AI marking is used, and whether a human checks it, is a school-wide decision rather than one teacher’s choice.
So is AI essay grading a bad thing?
Not by itself. Used as a first draft of feedback, which the teacher then reads, fixes and signs off, it can give students more feedback and give it faster. Several studies point that way, and the teachers who say their feedback improved are not imagining it.
The danger is AI marking that nobody checks, that nobody tells you about, and that you cannot appeal — inside a system that punishes students for using the very same tools. The technology arrived years before the rules. The rules are still missing.
Frequently Asked Questions
Can a teacher legally grade my essay with AI?
In most places, yes. No general law bans it, and few schools require the teacher to tell you. Some school districts have written AI rules that limit it or ask for a human check. So the answer depends on your own school’s policy, not on national law.
How accurate is AI essay grading compared to a human?
AI is steadier than human markers but only moderately close to expert scores. It does well on very strong and very weak essays and worst on middle-range work, which is where most students sit. It also drags unusual essays back toward an average grade.
Can AI grading be unfair to non-native English speakers?
Research on automatic essay marking has found scores can shift with a student’s English-learner status, race or family income. A student writing in a second language may lose marks for wording that a human marker would have accepted without comment.
How can I tell if AI wrote my feedback?
Look for feedback that is very long, shaped the same way for every student, full of general advice, and short on quotes from your own essay. None of these prove AI on their own, but together they are a fair reason to ask.
Should students be allowed to use AI if teachers do?
That is the fairness question schools now face. The usual answer is that marking is admin work while writing is the learning, so the two are not the same. Whether students accept that is another matter, and many do not.
