At the start of the exercise book the handwriting is shaky, the sentences broken. By the end of the year, and of the book, the work is neat and fluent. So far so normal, but Sharon Piper’s Year 3 pupil has travelled further than most: she arrived from Ethiopia a year ago unable to speak English.

That sort of progress - and Miss Piper can point to it in the work of pupils from Afghanistan, Kosovo and Somalia too - comes from trust and a homegrown assessment system developed by the staff of Cranford Park primary school in Hayes, Middlesex.

“If they had been to another school they might not have had the support,” says Miss Piper, the assessment co-ordinator, who works full-time with those whom Cranford calls its focus children: arrivals with little or no English.

“I can get them when they come in, find out about them and get them to trust me,” she says. No small task when dealing with those who may have known violence in their native lands. They are also strangers to anything like the English education system: some come into Year 5 having never been to school.

With 750 pupils, Cranford Park is one of the biggest primary schools in the country. Three quarters of its children are from ethnic minorities; more than a third take free school meals.

Despite this, the school achieves above national and education authority averages in its key stage 2 test results. Martin Young, the headteacher, points out that for certain pupils to reach Level 3 in Year 6 is a huge achievement.

“It’s not just Level 4 and above, although that’s important to us,” he says. “It’s also that child who was at Level 2 a year ago, but then is a Level 3 a year later, making twice the expected progress.”

The school makes the most of its ethnic diversity in artwork and displays.

Outside Mr Young’s office, shelves carry a collection of foreign objects: from carved statuettes to musical instruments, brought in by staff and pupils.

Cranford Park’s system of assessment for learning did not come in a handy package, says Mr Young. It evolved long before personalised learning became a New Labour buzzphrase.

“We as a group of professionals know in great detail the particular needs of the children at our school, and what we have tried to do is to grow an assessment system around those needs,” he says.

“The key is when a piece of work is done, whether it’s writing or a model in design technology, that we are explicit with the child. What features create quality? What is it about that piece of writing that makes it successful? So we reflect that back to them.

“The role of the teacher is to plot out the route ahead for the child to go that step further. It could be ‘Fantastic use of adjectives in that piece.

Last week we talked about adverbs. Have you ever thought of including those in your writing?’ ” Pupils with English as an additional language are coaxed by clear, careful marking. Mr Young says the system has feedback loops built in at all stages.

Trained bilingual classroom assistants play a crucial role in assessing individual children , how well they understood the previous lesson and where they may need support. There can be as many as three assistants in a class of 30. Until four years ago the school bought in local authority support for EAL pupils, but this lacked continuity and momentum. Now Sharon Piper stays with them across the key stages, keeping her own very detailed notes and data and feeding back to their class teachers on individual children’s abilities and progress.

She also develops techniques for helping pupils with EAL, whether it’s sticking detailed keys in the backs of books to explain the reward system of smiley faces, or drawing clear diagrams for visual support to help them understand the story of Treasure Island. And great care is taken in marking to feed back very clearly to every child individually, based on their ability with English. On one piece of writing she has written “you have used six adjectives, you have used two similes - well done.”

“With children who are advanced in English, God forbid that a teacher would be saying I want to see six adjectives and two similes. You would be controlling them too much,” she says. “But for a child in the early stages - to have that kind of scaffolding is very very useful.”