OET GUIDES · LAST REVIEWED 9 JULY 2026
OET writing correction: human tutors, AI marking, and how to use each
By the MedEngly clinical team, led by a UK based IMG doctor who came through this pathway.
Getting practice letters corrected is the part of OET Writing preparation that actually moves the grade, and it is also where candidates spend the most and waste the most. There are three routes: mark it yourself, pay a tutor per letter, or use AI marking. Each has a real place, and the cheapest mistake is using the wrong one for where you are.
This is an honest comparison of the three, from the point of view of the criterion feedback you need rather than the label on the service.
Marking it yourself: necessary but limited
Self marking against the published criteria is free and worth doing, because it trains you to read your own letter as an assessor would. Its limit is obvious: you cannot reliably see the errors you do not know are errors, and you cannot judge your own register or selection from the inside. Self marking is a supplement, not the whole loop.
Human tutor correction: high value, slow and expensive
An experienced OET tutor or ex-assessor gives the richest feedback: nuanced judgement on register, genuine calibration from having seen many scripts, and the ability to explain why a letter feels off. The cost is latency and price. Correction typically takes days and a single letter often costs the price of several, so the feedback loop is slow exactly when you need to iterate fastest, and few candidates can afford enough letters to build a habit.
Use human correction for depth at key moments: a diagnostic early on, and a check near your exam date. It is the wrong tool for daily volume.
AI marking: instant and cheap, with boundaries
AI marking against the six criteria returns per-criterion feedback in seconds at a fraction of the per-letter cost, which is what makes daily, iterative practice possible: write, see which criterion fell short, fix it, write again tonight. Its value is the speed of the loop, not a claim to replace an assessor.
The honest boundaries: any AI marker is an estimate, not an official evaluation, and quality varies a lot between tools depending on whether they are calibrated against real criteria or are thin wrappers. Treat the grade as indicative, look at the criterion feedback rather than the number, and prefer a tool that is transparent about how it is calibrated.
How to combine them without overspending
The efficient pattern for most candidates: use AI marking for volume and fast iteration on your weakest criterion, self mark to stay honest between sessions, and spend on one or two human corrections at the moments where nuance matters most, a diagnostic at the start and a confidence check before the exam. That gives you the loop speed of AI and the depth of a tutor without paying tutor prices for every letter.
What good correction feedback looks like, whatever the source
Regardless of who or what marks it, useful feedback shares a shape: a per-criterion breakdown rather than one impression mark, evidence quoted from your actual letter rather than generic advice, and a small number of prioritised fixes for the next letter rather than a wall of corrections. If your correction does not tell you which criterion to work on next, it has not done the job.
COMMON QUESTIONS
Is AI marking accurate for OET Writing?
It depends heavily on the tool. A marker calibrated against real criteria and reference scripts can give useful, consistent per-criterion feedback; a thin wrapper cannot. Any AI grade is an indicative estimate, not an official OET evaluation, so read the criterion feedback rather than fixating on the number.
How much does OET letter correction cost?
Human tutor correction commonly runs from around the price of a single lesson per letter, which adds up quickly across a preparation period. AI marking is far cheaper per letter, which is what makes daily practice affordable; the trade off is depth of judgement versus speed and volume.
Can AI replace a human OET tutor?
For fast, criterion by criterion feedback on many letters, AI marking does a job humans cannot do at that speed or price. For nuanced judgement and calibration at key moments, a human tutor still adds something. Most candidates do best combining them rather than choosing one.
How often should I get my OET letters corrected?
As often as you can act on the feedback. A fast loop of write, get marked, fix the weakest criterion, repeat, improves scores faster than occasional deep corrections you cannot iterate on. The feedback loop, not the volume of unmarked letters, is what moves the grade.
PUT IT INTO PRACTICE
Reading about the criteria is the start; seeing them applied to your own letter is what moves the grade. Get one letter marked against all six criteria, free, no signup.
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Independent preparation guidance based on publicly available OET materials; not affiliated with, or endorsed by, OET or Cambridge Boxhill Language Assessment. Regulator requirements change: confirm current scores with the regulator you are registering with.