The idea looks likely to be tried out in this country, as ministers try to encourage innovation.

Boston started by taking one troubled 1,600-student high school and carving it into three smaller schools, one on each of the building’s three floors. Each operates independently with its own staff, “instructional leader” and budget.

Life in the school “used to be chaotic, attendance was poor, there was teacher dissatisfaction”, says Kathy Mullin, assistant to the city’s superintendent for high school reform, who oversaw the changes. “Now kids are learning, and can clearly identify with the teachers.”

Test scores have begun to inch up, though it is too early to gauge whether real improvements have been made. “We’re obviously proud of the progress we’ve made, but we’re a little nervous that Boston is being touted as a model because we think we have a long way to go,” says Tim Knowles, the city’s deputy superintendent. “But the climate, quality of teaching, attendance, safety, discipline, drop-out issues, suspensions are all heading in the right direction.”

Boston’s 12 high schools have up to 1,600 students each. The city will break these into units of between 200 and 350. “Below 200, you lose the benefits of scale,” Mr Knowles says. “More than 350 and you’re back in a large school.”

The city has now received a five-year, pound;5.3 million grant from the Carnegie Foundation and from Microsoft founder Bill Gates, to continue reorganizing schools into smaller “learning communities”. The grant is being matched by local contributions, and Harvard’s graduate school of education has become involved. Five other US cities are also testing the idea.