The head of Weston Road high school in Stafford has spoken on the subject at numerous conferences, and earlier this year was in New Zealand, preaching the value-added gospel to heads and education officers.

“Like us,” he says, “they are trying to grapple with measures of prior attainment - this is what they were so keen about, looking at prior attainment rather than making judgments on socio-economic measures.”

It helps to understand Cooper’s approach when you know that he is a scientist. He graduated from Cambridge as a biochemist. Before he became a deputy head, he was successively a head of chemistry, a head of science, and an active member of the Association for Science

Education.

The further along the road of science you go, of course - and this comes as a disappointment to many pupils - the fewer bangs and smells there are, and the more rows of figures. A scientist, above all, is an interpreter of data.

Cooper says: “I have always been fascinated by data and I enjoy being in a data-rich environment.”

His Cambridge degree took him, at the start of his career in 1970, into a Southampton grammar school. But very soon he moved, following his principles, into the comprehensive system, where he has stayed ever since.

At first glance, it might seem that a keen analytical approach to pupil performance sits uneasily alongside the liberal philosophy that underlies comprehensive education. Cooper, though, sees things differently.

“Value-added strongly supports the comprehensive principle. It means we are registering the achievement of every pupil - the one who achieves a G grade having had an F predicted, just as much as the one who has an A* rather than an A.”

For him, this is the true purpose of value-added - not so much for more accurately comparing schools but as a means of focusing on the performance of individual pupils. “For setting targets at pupil level it is very powerful,” he says.

Cooper came to Weston Road as head in 1989, and immediately saw the need to raise pupil achievement. “In lots of ways the school was very good, but academically it was not achieving what it should have been. Exam results were below what you would expect.”

The scientist in him, though, wanted good data to support this impression.

He found the data he wanted through Durham University’s ALIS (A-level Information Service) and YELLIS (Year Eleven Information Service) which started at the end of the Eighties.

“In 1989 there was very little upon which to base comparisons. The opportunity to be part of the ALIS project in that year was a godsend.”

A couple of years later the school joined the YELLIS project at an early stage, and more recently has begun to use MidYis (Middle Years Information Service). “We were very much at the forefront,” he says. “Now a thousand schools use YELLIS.”

Today, he says: “All of these systems are a central part of our management. We couldn’t do without them.”

The systems present each year’s exam and test results as tables, graphs and scattergrams. These are examined at meetings between subject heads senior management. The numbers are scrutinised - looking backwards, to reveal, say, underperforming middle-ability pupils, and also forwards to set year-on-year targets for pupils. “It’s forced staff to ask questions they’ve never asked before - about the quiet pupil at the back of the class that we’ve missed, for example.”

The figures look formidable. The analogy is with a complicated balance sheet which is baffling to a layman, but in which a trained accountant can easily see all manner of interesting stories. To Cooper, obviously, his sheets of test and exam results have the clarity of a child’s picture book.

Not only that, but the important statistical principles, without which any set of figures can so easily be misused, misinterpreted or misunderstood are meat and drink to him. His colleagues, one assumes, have needed training and some persuasion.

“The staff were enormously sceptical back in 1990,” he says. But now they have seen the positive things that the system can tell us. It’s not a replacement for the teacher’s judgment - it actually makes it possible to make better judgments.”

There is training for staff - “We tend to provide mini-training sessions,” he says, “And each year there’s a 20-minute update for the whole staff. People are given ways to interpret what they see and each subject head has a member of the senior team to help.”

One of the potentially difficult effects of using value-added measures is that they highlight differences in performance between individual departments or teachers. Cooper is acutely aware of this and of the need for heads to run their schools so such comparisons are not threatening.

“You have to create a culture of trust - a climate within which no blame is allocated,” he says, going on to quote management guru W Edwards Deming.

“Deming says that where there’s fear you get the wrong figures.”

The assumption is that where the figures reveal a problem, the department, or the individual, will themselves see what has to be done. “That’s how we tackle it here - I suppose I’ve been fortunate in the people I work with.”

So has he seen the improvement he sought 10 years ago?

“There’s real evidence of steady improvement,” he says. “Not dramatic, but on a steady upward path. The school was considered a caring school then. I hope we’ve retained that. But I hope we show that we’re not just caring for people’s well-being but for their attainment as well.”