All heads and teachers know about self-evaluation. It runs through school life, encompassing not only Ofsted's statutory requirements, but also ideas about departmental self-review, pupils as independent learners, positive engagement with parents and, of course, pupil voice.
But how many know the extent to which its growth, and the movement away from confrontational top-down inspection, can be largely credited to one professor of education and his team?
John MacBeath, chair of educational leadership at Cambridge University since 2000, was formerly director of the University of Strathclyde's Quality in Education Centre. It was there in the late 1980s that he and his colleagues developed a framework for school self-evaluation acceptable both to schools and to those responsible for them.
Professor MacBeath's evangelical belief in self-evaluation is of a piece with his broader conviction that children and teachers learn best when they have freedom to shape their learning together in the classroom. It is a philosophy that harks back to his roots: first as a pupil in Glasgow ("We had so much to say about the quality of our school and never had a chance to say it.") and later as a teacher at Paisley Grammar School.
These experiences led him, as a lecturer at the then Jordanhill College in the early 1970s, to set up the Barrowfield Community School, a democratically organised haven and learning centre for 25 disaffected and excluded children in Glasgow.
"It was very influential for me," he says. "I saw how much even the lowest achieving children could contribute, and how passionately interested they were in their education when given the freedom to pursue their own interests."
Over the years, that conviction became the driver for producing, at Strathclyde, a workable and effective set of tools for school self- evaluation. In the early 1990s, it was taken up by the Scottish inspectorate and became the nationwide system of self-evaluation known as "How Good is Our School?" - today familiar to all Scottish teachers as HGIOS.
In England, however, government through the early 1990s remained ideologically and explicitly committed to the need to tackle failing schools from the outside. Preferring the "big stick and little carrot" approach, they went for Ofsted and "naming and shaming".
But change was afoot. The early Ofsted model was expensive, unwieldy, and evidence from Scotland and around the world showed that self-evaluation really did work as a way to improve teaching and learning. Arguably, though, the drive to convert English national and local government to self-evaluation only really took off when the National Union of Teachers (NUT) committed its political experience and negotiating skills to the cause. Seeking a positive, practical and academically credible alternative to the Ofsted way, NUT education secretary John Bangs commissioned Professor MacBeath to replicate his Scottish work in a 1995 report: Schools Speak for Themselves.
Presented to the main party conferences in 1996, the document was treated with contempt by Conservative junior education minister Eric Forth, who threw away a prepared speech in order to castigate it. But by then local authorities were already adopting Schools Speak for Themselves as the developmental framework for schools that they were looking for. Newcastle's director of education David Bell, later to become chief inspector of schools and now permanent secretary at the Department for Children, Schools and Families, became an active enthusiast, seeing the framework introduced across Newcastle schools.
Then Labour came to power in 1997 and committed Ofsted at least to the beginnings of a form of self-evaluation, starting the journey that has brought school inspection to the present "light touch" system based on the Self Evaluation Form (SEF). For Professor MacBeath, though, it is all a very long way from "job done". Today's self-evaluation is, for him, still "top-down". What he would like, clearly, is for schools to look beyond making periodic checks on their performance, and instead to ask themselves constantly: how good is our learning?
"If that becomes a way of thinking, then you don't need this ritual approach of questionnaires and interviews," he says.
All of that, far-reaching though it is, tells only part of the John MacBeath story, because his expertise in - and desire to learn about - self-evaluation has led to his ideas and writings being sought by dozens of schools and governments across Europe and the rest of the world. Of all those projects, he singles out as particularly satisfying his work on developing self-evaluation in the traditionally authoritarian Hong Kong school system. He points to the development of a government website showing how various schools have put their own approaches to self- evaluation into practice. His favourite bit of video shows a 10-year-old girl describing with clarity and insight - and in English - the importance of "learning how to learn".
Deep down, Professor MacBeath is undoubtedly a radical. "I believe that we are failing schools, failing teachers and failing children by too much prescription, too much pressure, stunting the capacity for growth and creativity," he says.
Others have said that, too, over the years. But Professor MacBeath, rather than preach the revolution, has focused on producing a way to improve schools that both respects his philosophy and actually works within the system as we have it.
"I've seen self-evaluation's transformational power in 30 countries where I have worked with teachers and young people," he says. "I've seen them responding to the trust invested in them, almost always surpassing expectation, relishing the freedom to craft their own approaches to what they see as worth evaluating and worth improving."
It is a common characteristic of the thinkers in this TES series that, working always with the evidence, they have turned theory that was sometimes unconventional, sometimes politically risky, into solid and acceptable practice. Professor MacBeath is firmly in that mould.
John Bangs sums it up: "He has provided a very rigorous but teacher- sympathetic balance to the top-down, data-driven school improvement approach. But at the same time, he has retained massive respect from the Government. John really has, in a very quiet and strong way, made a massive difference and knocked off many of the rough edges of government policy."
School Inspection and Self-Evaluation: Working with the New Relationship by John Macbeath (Routledge, 2006)
Self-evaluation in the Global Classroom by John Macbeath and Hidenori Sugimine (Routledge, 2003)
Self-Evaluation in European Schools: A Story of Change by John MacBeath, Michael Schratz, Lars Jakobsen and Denis Meuret (Routledge, 2000, now published in 16 European languages).