Improving the quality of teachers is a preoccupation of governments around the world, with myriad training programmes available to prepare new staff or help experienced teachers to become school leaders.
But now a lauded scheme from England - which focuses specifically on heads of department, who can often be neglected - is attracting international attention as a way to boost teachers' abilities and students' results.
Key to the Teaching Leaders programme are the ideas that middle managers have much greater knowledge of individuals in their departments than those at the top and that they are better placed than school leaders to effect change "on the ground".
James Toop, the organisation's chief executive, said the scheme, targeted at schools with disadvantaged intakes, had proved highly successful in the five years since its launch in England and had led to students outperforming national averages. Now, he told TES, it was attracting attention from other countries across Europe and Asia.
Mr Toop said he was speaking to educationalists and officials who were interested in the idea in countries including Australia, China, Germany and several other European nations. He predicted that many would adopt the scheme within the next decade.
The US has been the quickest to seize on the idea and has already set up its own national version, known as Leading Educators, which is growing rapidly.
Pasi Sahlberg, a government education official from Finland, told the World Innovation Summit for Education in Qatar earlier this month that raising the calibre of teachers was not a "silver bullet" for improving standards. But many world leaders disagree and subscribe instead to the central message espoused by the influential 2007 McKinsey report into school improvement, that the quality of an education system cannot exceed the quality of its teachers.
Tom Shinner, a special adviser to England's current education secretary, Michael Gove, said that the idea of developing middle leaders had been picked up by Malaysia's government in its latest national Education Blueprint.
Mr Toop said that the idea of focused, intensive training for middle leaders to help improve teaching standards across a school was reaching a tipping point both at home and abroad. "The achievement gap is the gap within schools (rather than between them)," he said. "It is about consistency of teaching.
"It is those middle leaders, who will have a microscopic focus on every teacher in their department, who are going to really shift things. A headteacher can't line-manage 80 teachers effectively, which is what is supposed to have happened in some systems."
Mr Toop's scheme recently received another two years of government funding, which will allow it to train a further 930 middle leaders who will manage about 3,255 classroom teachers, more than doubling the cohort of 776 managers trained to date. Teaching Leaders is also expanding from its base in England's cities, further out into the country's deprived coastal towns and disadvantaged rural areas.
Mr Toop recently gave a presentation in Madrid to officials running the Organisation for Economic Cooperation and Development's Programme for International Student Assessment (Pisa), where delegates from the Netherlands and Canada expressed interest in the initiative.
In the US, the Leading Educators scheme is now operating in Louisiana, Kansas City, Washington DC, Houston and Denver; another two regions are expected to follow soon.
Nikki Diamantes, the US scheme's director of emerging services, told TES that they had been contacted by growing numbers of school districts keen to adopt the scheme. "We are learning more and more about the impact that empowering an amazing teacher leader has on their fellow teachers," she said. "It means the principal isn't trying to lead on their own any more."
Meanwhile, Jamaica's new school leadership college wants to strengthen the heads of department who already play an important role in the country's schools.