The OET Purpose criterion (0–3): how to make your letter's purpose clear and expand it
Purpose is marked from 0 to 3 and asks whether the reader can tell immediately why you are writing and what you want them to do, and whether that purpose is followed through later in the letter. State the reason and the request in your first one or two sentences ('I am writing to refer Mrs Ito for assessment and management of her worsening leg ulcer'), then expand it in the closing paragraph with specific actions. A purpose that only appears at the end, or stays vague ('for your information'), is the usual reason this mark drops.
What the Purpose criterion asks
Purpose is the only OET Writing criterion marked out of 3; the other five are marked out of 7. In plain terms, the assessor asks two questions:
- Is the purpose immediately clear? Within the first sentence or two, does the reader know who the patient is, why you are writing, and what you want from them?
- Is the purpose expanded? Later in the letter, especially in the closing, do you make the request specific enough for the reader to act on?
Because the mark range is small, a single structural problem, such as a request that only appears in the last line, can cost a large share of it. For how Purpose sits beside the other criteria, see the OET Writing criteria explained.
Weak and strong purpose statements
| Weak opening | Why it is weak | Stronger opening |
|---|---|---|
| I am writing regarding Mr Duarte. | No reason, no request | I am writing to refer Mr Duarte, 71, for review of his heart failure medication following a 3 kg weight gain this week. |
| Mrs Ito was admitted on 2 March with a fall. | Starts the story; the reader must guess why | I am writing to request ongoing dressing care for Mrs Ito, who is being discharged today with a venous leg ulcer. |
| I am writing for your information. | Vague; is any action needed? | I am writing to update you on Ms Byrne's discharge and to ask you to review her blood glucose readings at her appointment next week. |
| Please see Baby Amara. | Too abrupt and unspecific | I am writing to refer Amara Osei, aged 9 months, for urgent assessment of poor weight gain. |
A strong opening usually has four parts: action verb (refer, request, update, transfer), patient (name and age or key identifier), reason (the main problem), and, if relevant, urgency. For more examples by letter type, see opening sentence examples; for urgent cases, see urgent letter language.
Expanding the purpose
The opening states the purpose; the rest of the letter supports it, and the closing turns it into specific actions. Compare:
Not expanded:
I would appreciate your review. Thank you.
Expanded:
I would be grateful if you could visit Mrs Ito within two days of discharge to change her dressing, assess the ulcer for signs of infection and reinforce leg elevation. Please contact the ward if the wound deteriorates.
The expanded version tells the reader what to do, when, and what to look out for, all drawn from the case notes. See closing paragraph examples for more patterns.
Worked example
These case notes are invented for this guide.
Patient: Mr Rafael Duarte, 71. Lives with wife. Diagnosis: Chronic heart failure; type 2 diabetes. Admission 10–14 March: shortness of breath, ankle oedema. Treated with IV diuretic. Weight on discharge 78 kg. Medications on discharge: furosemide dose increased; metformin unchanged. Education given: daily weighing, fluid restriction 1.5 L/day, report weight gain >2 kg in 3 days. Writing task: As the discharge nurse, write to the heart failure nurse, Mr Paul Nakamura, requesting follow-up at home.
First draft opening (purpose unclear):
Mr Duarte is a 71-year-old man with chronic heart failure and type 2 diabetes who was admitted on 10 March with shortness of breath and ankle oedema.
The reader still doesn't know what is being asked.
Revised opening (purpose clear):
I am writing to request home follow-up for Mr Duarte, a 71-year-old man with chronic heart failure, who was discharged today after treatment for fluid overload.
Revised closing (purpose expanded):
I would be grateful if you could visit Mr Duarte within the next week to check his weight against his discharge weight of 78 kg, review his tolerance of the increased furosemide dose, and reinforce his 1.5-litre fluid restriction. He and his wife have been advised to report a weight gain of more than 2 kg in three days.
The body in between (admission, treatment, education) now reads as the reason for the request rather than a retelling of the admission.
Checklist before you finish
- The first sentence contains an action verb: refer, request, update, transfer, inform and ask.
- The patient's name and the main problem appear in the first sentence or two.
- If the case is urgent, urgency is stated at the start, not only at the end.
- The closing paragraph lists specific actions, drawn from the notes.
- Nothing in the body contradicts or distracts from the purpose; anything unrelated to it is a candidate for cutting under Conciseness & Clarity.
Practise and check your purpose
Choose a case from the medEmu practice case notes and write only the opening and closing sentences for it; then write the full letter. Check your letter: medEmu gives Purpose its own 0–3 mark, alongside the other five criteria, and marks problems on your own sentences with the fix and the reason. Your first letter is graded free without an account, and you get 5 more when you sign up. Grades are estimates for practice, not official OET results, and medEmu is not affiliated with OET.
Sources
This guide is medEmu's writing advice, not official OET guidance; all patients and case notes are invented. The criterion name and its 0–3 range are as OET describes them. For OET's official Writing assessment criteria, see oet.com.