To some it is a career move, to others it is a vehicle for school improvement, a chance to learn from good practice in other schools. Many would not consider it at any price. Becoming an additional inspector - an AI -for OFSTED is not an easy move.

The post was created in September 1995 to cope with a growing backlog of primary inspections and to answer criticism that too many schools were being slated by teams who had no relevant experience. Some primary heads saw the training as a way of coming to terms with the inspection process; others even hoped to improve it.

Less prescriptive than the old-style inspection, which was based on the secondary model, the new primary framework encourages inspectors to set aside their own views and look at how the school chooses to deliver its teaching objectives, and whether the school is operating effectively.

Says one AI: “When heads knew we were an AI team they welcomed us. They were reassured by the fact we were practising heads with relevant experience. ” Another adds: “The HMIs are very astute, with their feet on the ground, but I think our hands-on experience broadened the picture.”

Bob Knight, head of Chetwood Primary in South Woodham Ferrers, Essex, became an AI on a year’s secondment. His school had grown and changed dramatically in recent years and he felt he needed time to reflect on the changes. He says: “I had worked in the same area for nearly 18 years and needed to think about what I was going to do next. I wanted something that would add to my professional development.”

After a term’s training and working on an HMI-led team, the AIs in Mr Knight’s intake worked in pairs, taking turns to lead inspections. The HMI sat in on the early inspections, and as Mr Knight and his partner gained in confidence and experience, so the supervision became more arm’s-length, until the HMI was simply monitoring the paperwork.

In all, Mr Knight led 10 inspections, an experience he describes as “positive”. “I’m not saying the model we work with is ideal, but I think if an inspection is done properly then it’s a very specific framework which can help a school improve,” he says.

Liz Carriban holds similar views. Head of inner city Barford Primary in Ladywood, Birmingham, for the past six years, she says: “It was a privilege to see so much good practice in so many good schools.” But she adds that seeing a school through the eyes of an inspector was an unnerving experience. “You can see the state of people and the fear in their eyes. Many teachers are very stressed and very frightened.”

Unlike some of her AI colleagues, she will not be moving into a career in inspection. But she claims the OFSTED training will help her not only in moving the school forward but in developing management potential within the staff. “I’ve built up a really good management team, so I knew I was leaving the school in good hands. A year’s secondment gave my deputy the experience of running the school and helped her apply for headships. In fact she got one while I was away.”

Jill Forbes, head of Emerson Valley combined primary in Milton Keynes, applied for AI training to get back in touch with teaching and learning objectives. She claims that after eight years as a head she had become immersed in management and had lost sight of the curriculum. Being an inspector for a year has allowed her to refocus on what is important. “As an inspector I felt a real buzz in being able to unwrap a school, to peel back the layers like an onion to find out what really made that school tick,” she says.

Qualified as a registered inspector (RegI), she will not be applying for a full-time position as an inspector either. “The full OFSTED is extremely onerous, especially for small schools when when you are having to constantly revisit the same members of staff for different reasons,” she says. “I didn’t like the isolation of report writing; I miss the camaraderie of working in a school and decision-making in a busy environment.”

And she drops in a word of advice for OFSTED. “I would prefer to see mini-inspections that just concentrate on the school management team and the governors. You can then get a good idea about whether a school is failing or in need of a full inspection.”

What struck Mr Knight most forcibly during his time as an AI were the huge disparities in funding. Moving as far afield as Norfolk and Suffolk, inner London and Leeds, he was surprised to learn that heads in other authorities were managing schools on far less than he was getting.

“Resourcing is a very important issue,” he says. “Some heads are struggling with tight budgets and managing surprisingly well. But when one school is receiving Pounds 3,000 per pupil and another as little as Pounds 1,500, then you know who stands more chance of a quality education.”

For Mr Knight, going back to his school after a spell working for what he calls “the opposition” was a testing moment. “When I returned to school my staff expected me to come in wearing my inspector’s hat. But now they appreciate the fact that I’m willing to share my experience and work with them to help the school improve.”

Despite her decision to remain as a head, Liz Carriban will still continue with inspections. She did one inspection as a RegI last term - for a private inspection company - and, for a four-day inspection plus a lot of report writing in her own time, she earned a Pounds 3,600 fee for her school which she has earmarked for three new classroom computers.

But any further inspections will have to wait until her own school has been visited by OFSTED. She says: “The brown envelope arrived in the first week. I was away on secondment, so they agreed to put back the inspection until April the following year. I think me being an inspector is reassuring to staff, but so much depends on the dynamics of the individual team that you can never predict the outcome.”