How ClayLingua marks your IELTS Writing
When you submit a Writing test, your answer is checked for word count and then scored on four criteria. Each criterion gets its own score, and those scores are combined into one band. Below we explain each step, and which parts are judged by an AI model and which are measured from the text. If you want the examiner's view first, read the official criteria guide and the Task 2 structure guide.
Key insight
Our marking is built to show your weakest criterion. It is an estimate for practice, not an official IELTS score or an examiner's judgement.
Three steps, every time
Each Writing test goes through the same three steps.
- 1Step 1
Check the word count
Your answer is counted. Answers under the minimum word count are capped at a lower band. The caps are listed below.
- 2Step 2
Score each criterion
You get four separate scores: Task Response (or Task Achievement on Task 1), Coherence and Cohesion, Lexical Resource, and Grammatical Range and Accuracy.
- 3Step 3
Combine into one band
The four scores are averaged and rounded to the nearest half band.
Task Response (Task 2) or Task Achievement (Task 1)
This is the only criterion our system scores with an AI model. The model reads the question and your answer, then judges how fully and directly you address every part of the task. On Task 1 that means covering the key features of the information. On Task 2 it means answering the question clearly, with a position you support.
Coherence and Cohesion
Measured from the text. We count how many different linking words you use and whether you repeat the same ones too often. Varied linking that reads naturally helps the score. A string of the same connector pulls it down.
Lexical Resource
Measured from the text. We look at how wide your vocabulary is and whether your word combinations are natural. Basic words used again and again, where a more precise word or a natural combination would fit, lower the score.
Grammatical Range and Accuracy
Measured from the text. Grammar and spelling are checked by LanguageTool, an open-source grammar checker. We also measure how many different sentence structures you use. Both accuracy and range count, so a simple essay with no errors will not get top marks for range.
Averaging and the word-count caps
The four criteria are averaged and rounded to the nearest half band. If your answer is under the minimum word count, the overall band is capped as follows:
- Under 50 words: at most band 4
- Under 100 words: at most band 5
- Under 80% of the minimum (120 words for Task 1, 200 for Task 2): at most band 6
Note
The cap only lowers a band. Length never raises it.
Use it for direction, not as your IELTS score
- It is not an examiner. The score is an estimate for practice, and it can differ from an examiner's band.
- It is not an official IELTS score, and it does not replace one.
- The text measures can be wrong. A grammar checker may flag a correct structure, and a repeated word can be a deliberate choice.
- Use it to find your weakest criterion, then check your writing against the official criteria guide.
A worked example
These numbers are made up to show the arithmetic. They are not from a real essay.
- Task Response: 6
- Coherence and Cohesion: 6
- Lexical Resource: 5.5
- Grammatical Range and Accuracy: 6
- Average: 5.875, rounded to an overall band 6
Key insight
Lexical Resource is the lowest score here, so that is the criterion to practise first.
How to use your feedback
Most of the improvement comes from working on your lowest criterion, not your highest.
- 1Step 1
Find your lowest criterion
Look at the four scores. The lowest one is where a week of practice will change your band the most.
- 2Step 2
Practise that criterion
Use the matching lessons and drills. For Lexical Resource, work on word choice and phrases. For Coherence and Cohesion, work on linking ideas.
- 3Step 3
Write again and compare
Take another Writing test and check whether the lowest criterion has moved.
Mark a Writing test yourself
Take a timed Writing mock test and see the four scores, the word count and the feedback for each criterion.
How we check the marking
We test the marker against known essays. Sample scripts from the IELTS Academic Writing Sample Tasks 2023 are scored in our test suite, and a band 4 script must score below a band 8 script. This follows the approach in published research on automated essay scoring, which checks machine scores against human marks. The vocabulary checks use word levels from the CEFR-J and New General Service List word lists, and the grammar checks use LanguageTool. The sources are listed below.
How ClayLingua marks Writing: questions
Is the score my IELTS band?
No. It is an estimate for practice. Only an official IELTS test gives an official band.
Does an AI mark my essay?
An AI model scores Task Response. The other three criteria are measured from the text, using rules and a grammar checker.
Why was my band capped at 5?
Your answer had fewer than 100 words, so the band is capped at 5. Length does not raise a band, but a very short answer cannot score as high as a full one. Write at least the minimum for your task.
Can I trust the score?
Use it as direction. Look at your scores across several tests rather than trusting one result.
Sources
- IELTS Writing band descriptors, Task 1 and Task 2 (public version). The public criteria that the four scores are named after
- LanguageTool. The grammar and spelling checker used for Grammatical Range and Accuracy
- New General Service List and New Academic Word List. Word lists behind the vocabulary level checks for Lexical Resource
- IELTS Australia: how your IELTS Writing test is marked. How the official Writing test is marked, to compare our four criteria against
- Automated Essay Scoring With e-rater v.2. Published research on checking automated essay scores against human marks, the method behind our calibration tests
- CEFR-J English word list. A1 to C2 word levels used to measure vocabulary range
Get a writing plan built around your weakest criterion
A day-by-day plan built on your scores and exam date, with the Writing lessons, drills and mock tests for the criterion holding you back.
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Your overall IELTS target.
