Accurate AI marking for teachers is essential because assessment affects student confidence, teacher workload and school trust. A useful AI marking tool must be fast, but it must also be close enough to examiner judgement that teachers can use it as a dependable first pass.
Graded Pro publishes real accuracy data rather than vague claims. On its Accuracy page, the platform reports testing against official IGCSE and GCSE examiner results, using 387 questions across maths and English. The headline result is a Quadratic Weighted Kappa of 0.97, a statistic widely used to measure agreement between markers.
Teachers searching for accurate AI marking for teachers are not only looking for faster marking. They need feedback they can trust, marks that are close to examiner judgement and a workflow that still allows teacher moderation. If AI grading is inaccurate, it can damage student confidence, create extra checking work and make assessment less fair.
According to the Graded Pro Accuracy page, the platform achieved a 0.97 Quadratic Weighted Kappa across 387 questions and a 0.97 correlation with official examiner marks. It also reports no statistically significant difference from the examiner marks in the tested sample, with p = 0.12.
Structured questions are one of the strongest areas for AI grading because there are defined marks, expected steps and clear evidence to check. Graded Pro reports a 0.26 average error per structured question and says 95% of structured-question marks were within plus or minus 1 mark of the examiner.
This matters for teachers marking maths, science, retrieval tasks, short-answer questions and multi-step exam problems. It means AI can handle a reliable first pass across a whole class set, while the teacher checks samples and unusual answers.
Graded Pro is clear that levelled questions and essays are harder for any marker, human or AI. The published accuracy page recommends reviewing extended writing, particularly the strongest responses at the top of the mark range, where the AI can occasionally under-mark by a few marks.
That is a sensible teacher-led position. Accurate AI grading should not mean blind automation. It should mean faster first-pass marking, transparent feedback and professional judgement where nuance matters most.
Accurate AI marking is not about removing teacher judgement. It is about giving teachers a strong, evidence-based first pass so they can focus review time where it matters most.