Britain's Reading Recovery initiative is one of the world's best programmes for struggling readers, an international study has found.
The finding is a boost for the literacy scheme, which is at the heart of the government's Every Child A Reader programme yet has been criticised by some academics who question its value for money.
The report, published by the University of York's Institute of Effective Education this month, concluded that Reading Recovery, which involves specially trained teachers working one-to-one with pupils using a mix of methods, is one of three for which there is strong evidence of effectiveness.
It adds that the effect is most obvious in recent studies, which use an updated version of the programme in which more phonics teaching has been introduced.
Professor Robert Slavin, director of the institute, said: "The two UK studies on Reading Recovery are very positive, but the US studies done in the 1980s and 1990s are not. The earlier Reading Recovery programme had very little phonics."
The team from York University and John Hopkins University, Baltimore, looked through 96 evaluations of reading programmes.
Professor Slavin, who also founded the Success for All reading programme, added: "People have the idea that if you do something fabulous in Year 1 then they are set up for life. But if you are cooking a stew and you turn it on at a very low temperature it will never cook. And if you turn it on a very high temperature all the time, it won't cook either. You need to get it to the boil and then simmer it."