AT CHARTER Academy, a small, immaculately kept secondary school in Portsmouth, children who qualify for free school meals—63% of the school’s pupils—are also given a free uniform. Mums are invited in to chat about their children’s progress over a glass of wine; dads prefer watching their children on boxing nights, says Dame Sharon Hollows, the school’s headteacher. “A lot of the parents had a poor experience at school, it’s about making them feel more comfortable,” she adds. If a child is taken into care, someone from the school takes them shopping to make sure they have enough clothes. When a child doesn’t turn up to school, staff head out in a leased car to look for them. The turnaround has been fast: in 2009, the year the school became an academy, 23 children applied for 120 places; last year, 200 applied. During a 2014 visit to the school, the prime minister, David Cameron hailed the “extraordinary achievement”.

Some of these measures would have been introduced anyway, but many have been made possible by the huge boost to the school’s funding provided by the “pupil premium”, says Dame Sharon. The policy was introduced by the Conservative-Lib Dem coalition in 2011 to improve the academic performance of the poorest children. Schools receive additional funding for every child on free school meals (now £1,320—or $1,850—for primary schools, and £935 for secondary schools) and can spend the money how they see fit, with parents, governors and inspectors keeping tabs. In 2014-15, £2.5 billion was spent on the policy, 6% of the schools budget. Nick Clegg, the former deputy prime minister, called the premium one of his proudest legacies.

Evidence suggests academic progress may be slow. The gap between children on free school meals and others at GCSE—the exams taken aged 16—has remained high if measured by the percentage of children attaining five A*-C grades. Indeed, the gap between the performance of rich and poor children in Britain is larger than average for the OECD club of mostly rich countries. But there are signs of progress: the gap in exam results taken aged 11 has narrowed, as has GCSE performance if measured by results in eight core subjects.

Headteachers appreciate the flexibility the funding gives them. “It has allowed us to be much more creative, to take more risks,” says Hazel Pulley of Parkfield Community School in Birmingham. One of the school’s successful interventions was hiring teachers to work solely on communication in early years, since most of its pupils don’t speak English as a first language. Many schools use the money to help individual pupils: one in Sheffield bought a bike for a pupil struggling to care for his siblings and get to school on time.

Meanwhile, the government has poured funding into studies looking at how best to spend money, providing the Educational Endowment Foundation (EEF), a charity, with £137m. It collates evidence from abroad and funds studies at home: around one-quarter of English schools are involved in randomised control trials run by the charity.

Schools increasingly turn to the research for guidance: two-thirds now consult the EEF’s advice, up from one-third in 2012, according to a report by the National Audit Office (NAO), which scrutinises government spending. Surveys by the National Foundation for Educational Research, a charity, found that the most common interventions in the first years of the pupil premium were to reduce class sizes and increase numbers of support staff—neither of which are judged to be effective by the EEF. Now schools are more likely to put in place one-to-one tuition and pupil feedback—both of which are highly rated.

Yet, for some headteachers, “the idea that you turn to evidence is just not part of the culture,” says Sir Kevan Collins of the EEF. A number of cheap, effective approaches, such as using older children to tutor younger ones, are still rarely used. Some 44% of schools have spent part of the pupil premium sprucing up classrooms or the school environment, which has little impact on student performance. Nearly eight in ten schools use the extra money to support activities that benefit all pupils, which makes sense only where there are many pupils on free school meals.

Some argue that pupil-premium spending should be subject to tighter scrutiny. Others suggest that schools have become too reliant on research by the EEF for evidence of what works. Yet such debates are partly proof of the premium’s success. How to raise the attainment of children from poor backgrounds is now a focus for educators. Before the premium, 57% of school leaders said they aimed support at their most disadvantaged pupils; 94% now do, says the NAO. With such a wide gap in attainment between children from rich and poor families, that is no bad thing.