Three reading schemes - using coaching, free books and specialist teaching to bridge the gap between primary and secondary literacy levels - made no difference to children's progress, with one even leaving students lagging behind their peers, research has shown.
The trials, which received pound;1 million of funding from the Education Endowment Foundation charity, also revealed the difficulty of coordinating help for struggling readers during the transition from primary to secondary.
This year, 33,444 pupils started secondary school in England with reading skills at level 3 - approximately two years behind the expected level. A further 27,870 children, including those with special educational needs, were at an even lower level.
The 510 students taking part in one of the projects - the TextNow Transition programme - had a 20-minute, one-to-one coaching session with a volunteer every weekday for five weeks at the end of primary and again for 10 weeks at the start of secondary. They were also given access to a website where they could take quizzes, enter competitions and buy books using credits earned during coaching sessions.
By the end of the scheme, however, there was no evidence that literacy had improved or that the participants had developed a more positive attitude towards reading. In fact, children who were not eligible for free school meals made an average of three months' less progress than those in the control group.
Academics also found that children could be resentful of the initiative because they were removed from classes and missed out on activities with friends.
The same team of evaluators from Sheffield Hallam University and Queen's University Belfast also carried out a study of the Summer Active reading programme delivered by Booktrust.
Under this scheme, children were given four sets of free books between the end of Year 6 and the start of secondary school. Again, there was no evidence of an impact on reading skills, although researchers said it was not possible to say that the programme was ineffective because of the small sample size.
A third initiative, Vocabulary Enrichment Intervention, aimed to improve the reading abilities of 649 Year 7 pupils who had not reached the expected level 4 at the end of primary school. English lessons were replaced for three half-terms with specialist sessions on widening vocabulary, improving phonics strategies and practising reading, writing, speaking and listening. Nevertheless, no impact on pupils' reading was found.
David Harris, a former headteacher and author of transition guide Are You Dropping the Baton?, said: "I'm sure these projects were very well-meaning and if they were used as part of a bigger project they could be good, but transition is bound to disrupt a child fundamentally."
He added: "It's like saying to your 11-year-old son or daughter, `Thanks for the last 11 years, now if you go down the road and knock on the second door on the left, that is your new home.' We know that would be a disaster but that's effectively what we do at school."
Mr Harris said the best way to support children was to get together and plan coherent responses to their needs.
Stephen Logan, assistant headteacher of Malet Lambert School, a secondary in Hull, said transition projects at his school started in Year 5 rather than Year 6.
He explained: "It's not just about what primaries can do for secondaries, it's about asking primaries what can we do to support them. We have 300 children arriving next year. We have to make sure they feel safe and comfortable."