There is a lack of rigorous research into what works for struggling readers, specialists have told MPs.
Giving evidence to a select committee, the experts supported Reading Recovery, the programme at the heart of the Every Child a Reader initiative, which has been increasingly controversial after some academics questioned whether it was cost-effective.
The Government has spent #163;144 million on rolling out both Every Child a Reader and the numeracy programme Every Child Counts.
But the Commons' science and technology sub-committee wanted to know whether literacy programmes were tested using randomised controlled trials, the type of research used in medicine.
They were told that such trials had been carried out in the United States, but compared Reading Recovery with doing nothing, not with other interventions.
Jean Gross, director of the Every Child a Chance Trust and the Government's incoming communication champion, said: "There are a number of programmes that are open to schools to choose. We may be looking for a magic bullet or the best buy, but there will not be a best buy. There will be different things that work at different levels of reading.
"Last year, this programme reached 12,000 children and 78 per cent of them got back to the level of their peers. Are we going to do randomised controlled trials on all those children against 40 programmes?"
She also called for an educational equivalent to the medicine testing house, the National Institute for Health and Clinical Excellence.