AI vs teacher marking: what 500,000 IGCSE papers taught us
Over the past year, more than 500,000 IGCSE papers, across all subjects, were marked twice on The Learning Mate: once by our AI and once manually by teachers. Where the two marks disagreed, a senior reviewer decided the correct mark against the mark scheme. Checked question by question against that final mark, the AI was correct on more than 97% of questions, more often than the original manual marking.
This page explains how the comparison worked and what the numbers mean.
The headline numbers
| Questions marked correctly (vs final reviewed mark) | |
|---|---|
| The Learning Mate AI | More than 97% |
| Papers compared | More than 500,000 IGCSE papers, all subjects |
| Period | The past year (to October 2026) |
How the comparison worked
- Every paper was marked twice. The AI marked each script question by question against the mark scheme. Teachers also marked the same scripts manually.
- Marks were compared per question, not per paper. Per-paper totals can hide errors that cancel out, such as one mark too many on Question 2 and one too few on Question 5. Comparing per question doesn't.
- Disagreements were adjudicated. Where the AI and the teacher gave a question different marks, a senior reviewer decided the correct mark against the mark scheme.
- Accuracy is the share of questions where a marker's mark matched the final mark. Where the AI and the teacher agreed, that mark was accepted as final.
What the numbers mean
- The AI applied the mark scheme more consistently than manual marking did. Across hundreds of thousands of questions, it matched the final mark more often.
- This is not a criticism of teachers. Manual marking happens late at night, in bulk, under time pressure, and often for papers outside a teacher's main specialism. Inconsistency between human markers is well known. It's the reason exam boards train and monitor their examiners so closely. An AI doesn't get tired at script 28.
- Consistency is where AI helps most. Point-marked questions make up the bulk of most IGCSE papers. Applying the same rule to the 30th script exactly as to the first is hard for a tired person and routine for an AI.
- Results vary by paper. Subject, question type, mark scheme quality and handwriting all play a part. See what AI handles well in handwritten scripts.
Why we stopped offering human-verified marking
We used to offer a human-verified grading mode, where a person checked the AI's marks before they reached the teacher. We retired it once this data showed that the AI on its own was more accurate than manual marking. Teachers stay in control: any mark or comment can be changed, and results reach students when the teacher publishes them.
See it on your own scripts
The quickest way to see the difference is on papers you've already marked. Our 10-script test takes one afternoon:
- Take ten scripts your department has already marked.
- Run them through The Learning Mate with the same mark scheme.
- Compare question by question.
You can start with one paper at thelearningmate.com/trial, with no account needed.
The study at a glance
| Item | Detail |
|---|---|
| Scope | More than 500,000 IGCSE papers, all subjects |
| Period | The past year, to October 2026 |
| Markers compared | The Learning Mate AI and the teachers who marked the same scripts manually |
| Unit of comparison | Individual questions, not paper totals |
| Reference mark | The final mark: agreed marks stood, and a senior reviewer settled every disagreement against the mark scheme |
| Result | The AI matched the final mark on more than 97% of questions, more often than the original manual marks |
How to cite this study
If you reference these figures, please cite the study as:
The Learning Mate (2026). AI vs teacher marking: what 500,000 IGCSE papers taught us. A per-question comparison of AI and manual marking on more than 500,000 IGCSE papers, all subjects, in the year to October 2026, against an adjudicated final mark. https://thelearningmate.com/blog/ai-vs-teacher-marking-accuracy-igcse
FAQ
How accurate is AI marking for IGCSE papers?
In our comparison of more than 500,000 IGCSE papers over the past year, The Learning Mate's AI matched the final reviewed mark on more than 97% of questions. That is higher than the original manual marking by teachers.
How was accuracy measured?
Each paper was marked by the AI and manually by a teacher. Where they disagreed on a question, a senior reviewer decided the correct mark against the mark scheme. Accuracy is the share of questions where a marker's mark matched that final mark.
Is AI marking more accurate than teachers?
In our data, yes: the AI matched the final mark on more than 97% of questions, more often than manual marking did. That reflects the conditions of manual marking, such as volume, time pressure and fatigue, rather than teachers' expertise.
Why did The Learning Mate stop offering human-verified grading?
We retired the human-verified mode once our data showed the AI alone was more accurate than manual marking.