EXTENSIVE studies south of the border reveal exam results generally plateau after three years' efforts to raise standards, Professor John Gray, a key Cambridge University researcher, told a school improvement conference in Stirling last week.
Ministers and the public may demand ever higher results, so long as standards do not fall, but achieving year on year progress was difficult for most schools.
Professor Gray, a former researcher at Edinburgh University, said: "A lot of the time, after a year or two, things begin to slow down and that's the crucial time for the continuing development of the institution.
"Three years seems to be a good run for school improvement. If you sustain it for a fourth year, you have done particularly well
and if you make it for a fifth year, it is worth travelling across the country to see what you are doing," he said.
In a keynote address to the conference, organised jointly by the Association of Directors of Education in Scotland and the Institute of Education at Stirling University, Professor Gray said he believed comparative progress was difficult when almost all schools were committed to improvement.
Studies in England, however, showed three factors made a difference: focusing on exams and "playing the game"; changing teaching and learning; and giving pupils responsibility for learning.
Other factors such as involving parents, the style of senior managers and restructuring middle management or integrating academic and pastoral responsibilities were of "borderline significance".
Those of even less significance were the nature of the school mission, the learning environment and resources, providing extracurricular activities, building relationships with external agencies and the structue and content of the curriculum.
Professor Gray later told The TES Scotland: "Changes at classroom level matter more than anything else. It's how you motivate pupils through your teaching, how you broaden and expand your repertoire of teaching skills. Teachers need to constantly improve their practice, and the schools that were improving rapidly were those making changes in classroom practice."
He added: "It's changing the structure of teaching, bringing in new resources, changing the variety and pace. Lots of teachers are doing these things but what was striking was that whole staffs were doing it."
In the most improving schools, teachers were encouraging pupils to take charge of their own learning, pushing the value of homework, passing on knowledge and skills about the process of learning and helping them to monitor their own progress.
Some schools emphasised exam techniques and teaching and learning, others said more pupil responsibility was more important.
"There is no blueprint. Schools will have to discover their own. We have to encourage the view that there are several routes to improvement and the chances are that past performance is not a very good predictor of future performance," Professor Gray said.
Not all schools which had shown significant improvement had changed headteachers, although some had.
The professor urged Government and local authorities to engage at classroom level and to help to change the culture of schools. "We tend to focus on the symptoms of failure but never get to the heart of the failing school," Professor Gray said.
Studies of English schools in "special measures" showed it was possible in some primaries to get schools back on track in a relatively short period due to the combination of public attention and professional commitment, but progress at secondary level was "very modest".