OET Writing is graded on four sub-criteria: Purpose, Content, Conciseness and Clarity, and Language. Each one is marked separately on a scale from 0 to 5, and your overall letter grade — A through E — is derived from the combined performance across all four. Knowing exactly what examiners look for under each criterion is more useful than practising blind repetition of referral letters.
The test gives you one writing task: produce a professional healthcare letter (most commonly a referral) in 45 minutes, using information from a case notes stimulus. The letter must be addressed to a named recipient and serve a clear clinical purpose. What separates a Grade B from a Grade C — and Grade B is the threshold most registration bodies require — is usually a failure on one or two specific sub-criteria, not across the board.
How Is OET Writing Scored? The Sub-Criteria Explained
Each of the four sub-criteria is awarded a score from 0 to 5. Those four scores are averaged to produce an overall mark out of 5, which then maps to a letter grade: A (4.5–5), B (3.5–4.4), C (2.5–3.4), D (1.5–2.4), E (0–1.4). A candidate who scores 5 on Language but only 2 on Content will still land in Grade C or below. This is why targeting your weakest criterion is more efficient than polishing your strongest.
| Letter Grade | Mark Range (out of 5) | Common Registration Requirement |
|---|---|---|
| A | 4.5 – 5.0 | Some specialist councils |
| B | 3.5 – 4.4 | Most medical/nursing boards worldwide |
| C | 2.5 – 3.4 | Below standard for most bodies |
| D | 1.5 – 2.4 | Well below standard |
| E | 0 – 1.4 | Failing |
Sub-Criterion 1: Purpose
Purpose assesses whether the reader immediately understands why the letter has been written. A high-scoring letter states the reason for contact in the opening sentence, names the patient, and makes the clinical request or information transfer explicit. Examiners penalise letters where the purpose only becomes clear by paragraph three, or where it is implied but never stated. For a referral letter, a score-5 opening looks like: 'I am writing to refer Ms Anna Becker, a 54-year-old physiotherapist, for urgent assessment of a suspected deep vein thrombosis.' That single sentence answers who, why, and how urgent — all before the body of the letter begins.
Draft your opening sentence last, after you have read all case notes. This ensures your statement of purpose reflects the most clinically significant information, not just the first detail you noticed.
Sub-Criterion 2: Content
Content assesses the selection and relevance of clinical information transferred from the case notes. A score of 5 requires that all essential information is included, no irrelevant details appear, and the information is accurately represented. Examiners apply a document called the Marking Guide for each task, which pre-identifies the essential points. Missing more than one essential point drops you to a 4; including significant amounts of irrelevant material or misrepresenting clinical facts drops you further. There is no credit for inventing information not in the notes.
Do not include every detail from the case notes. Copying in routine observations (e.g., 'patient was cooperative during examination') when they are clinically irrelevant actively harms your Content score by signalling poor professional judgement.
Effective Content selection means asking for each note item: 'Does the recipient need this to act appropriately?' For a referral to an orthopaedic surgeon, the patient's smoking history may be relevant to surgical risk; their childhood chickenpox history probably is not. This clinical reasoning skill is exactly what the sub-criterion rewards.
Sub-Criterion 3: Conciseness and Clarity
Conciseness and Clarity examines how efficiently and unambiguously the information is communicated. This is the criterion most often underestimated by test-takers. It is not simply about being brief — a 150-word letter can score poorly here if sentences are tangled, and a 250-word letter can score 5 if every sentence delivers one clear idea. Examiners look for logical sequencing (typically: reason for referral → relevant history → current status → investigations → request/action), appropriate paragraph breaks, and absence of ambiguous pronoun references or run-on sentences.
Low Conciseness & Clarity (Score 2–3)
- Information presented in the order it appears in the case notes, not in clinical priority
- Excessive hedging: 'It might possibly be considered that...'
- Two or three clinical issues merged into one paragraph
- Pronoun ambiguity: 'She told her that her results were concerning'
High Conciseness & Clarity (Score 4–5)
- Opening paragraph states purpose; subsequent paragraphs follow clinical logic
- Direct professional register: 'I request urgent MRI of the lumbar spine'
- One topic per paragraph; clear signposting when topic changes
- Explicit nouns used where pronouns could create confusion
After writing your letter, read each sentence aloud and ask: 'Could a busy specialist misread this?' If yes, rewrite before moving on. Clarity errors are almost always fixable in the final 5 minutes of your 45-minute window.
Sub-Criterion 4: Language
Language is the only sub-criterion that directly assesses English grammar, vocabulary, spelling, and punctuation. A score of 5 requires that the letter reads as natural, professional clinical English with no errors that impede communication, and minimal minor errors. A score of 4 — still sufficient for Grade B — allows for occasional errors that do not distort meaning. A score of 3 indicates frequent errors that sometimes interfere with the reader's understanding, which typically results in a Grade C overall if the other criteria are solid.
Critical language features for OET letters include: correct use of medical terminology (misusing a clinical term is worse than using a general one correctly), consistent formal register throughout (avoid contractions, colloquialisms, and first-name-only patient references after the introduction), and accurate verb tense control when narrating patient history versus current presentation. Past simple for history, present simple for current status, and conditional constructions for recommendations are the three tense frames that cover most of a referral letter.
Spelling errors on drug names, diagnoses, or anatomical terms are penalised more heavily than general spelling errors because they signal clinical risk. If you are unsure of the exact spelling of a medication in the case notes, copy it character-by-character from the stimulus — you are permitted to use the case notes during writing.
How to Prioritise the Four Criteria in Your Preparation
Most candidates arrive at OET Writing with reasonable Language competence — they can write grammatically — but lose marks on Content selection and Conciseness. A structured preparation approach works as follows.
- Benchmark first: write one full letter under timed conditions, then self-mark against each sub-criterion using the official band descriptors available on the OET website.
- Identify your lowest sub-criterion score — that is where your preparation effort should be concentrated, not spread evenly.
- For Content, practise annotating case notes before writing: mark each item E (essential), R (relevant but non-essential), or I (irrelevant). Aim to include all E items and selectively use R items.
- For Conciseness and Clarity, practise rewriting one paragraph per day from a past letter, reducing word count by 20% without losing any clinical meaning.
- For Language, build a personal error log from every marked letter and review it before each practice session — recurring errors are the fastest wins.
- For Purpose, memorise two or three opening sentence templates that cover referral, discharge, and follow-up scenarios, then adapt them to each task rather than writing from scratch under pressure.
Memo Chat+ provides OET Writing practice tasks with detailed feedback mapped directly to these four sub-criteria, so you can see exactly which criterion is costing you marks on each attempt rather than receiving generic comments. Targeted, criterion-specific feedback is the single fastest route from Grade C to Grade B.