Like all good heads, Pat Collarbone arrives early at school. One day, she fell into conversation with one of a group of girls who had also arrived early. They discussed the book the girl had been reading. A few days later, the group had grown: all of them were gathered around their head, talking about books.

That is very much Pat Collarbone’s way. “Education is not something done to children - it’s something done with them,” she says. “I see the head as the lead learner of the institution.”

Mrs Collarbone, who is currently head of Haggerston School in the London borough of Hackney, will be in a unique position to spread that gospel when she takes charge this autumn of a regional leadership centre for current and aspiring headteachers in the capital.

Set up at the London Institute of Education’s International School Effectiveness and Improvement Centre, the new unit will focus on what everyone agrees is the crucial ingredient in a school’s success: the quality of the head. It will run conferences, seminars and “mentoring” schemes, with its work closely linked to the new professional qualification for heads.

Mrs Collarbone is one of the chief gurus of the art of school improvement, having spoken on the subject to a range of audiences including Her Majesty’s Inspectorate and the Office for Standards in Education. She is a member of the Department for Education and Employment’s advisory committee on improving schools.

Her reputation is based on solid achievement in the school to which she has devoted virtually all her working life. Haggerston is a 900-pupil girls’ 11-16 comprehensive in the most deprived part of Hackney, where pupils speak a total of 34 different first languages.

Starting there in 1968 as a geography teacher, she spent two years as an adviser with the Inner London Education Authority before returning to the school as deputy head in 1984.

It was when she was appointed head in 1990 that the school began to change from what she describes as “a good, secondary modern-type school” to a true comprehensive. With her motto, ACHIEVE (Attendance, Commitment, Homework, Improvement, Effort and Valuing Everyone), she set about inspiring everyone with her vision of high standards for all.

“Since she has been head, it’s been ‘light the blue touch paper and off we go’,” says Sue Warrington, her deputy. Since 1992, exam results have improved from 20 per cent of pupils getting five A-C grades at GCSE to 38 per cent, which put Haggerston among the top 20 improving state schools last year.

After six years as head, Mrs Collarbone is ready for another new challenge. She starts at the new leadership centre part-time in October, full-time from next January. But before she leaves, she faces in September the greatest challenge of any headteacher: a visit from an OFSTED inspection team.

“It’s clearly something I would never wish to miss,” she remarks. “I’m sure there will be stresses but it’s quite good to have people coming in and doing an audit.”

Michael Barber, who runs the London Institute’s school-improvement centre, describes Mrs Collarbone as “the best head I’ve ever had the pleasure of coming across”, adding: “She has the right combination of toughness in setting standards and the personal skills to bring people with her.”

Her deputy, Sue Warrington, describes Mrs Collarbone as “inspirational” and “rigorous”.

Will even Chris Woodhead, the chief inspector, dare to venture a word of criticism?