A study into integrating local children's services by the National Foundation for Educational Research (NFER) has found that so far most of the impact has been on councils rather than on children.
And it is the most vulnerable pupils who are missing out.
The findings were presented at this week's North of England Education Conference in Cardiff, where schools minister Jim Knight was yesterday expected to talk about implementing the Government's new Children's Plan. But the NFER study, carried out on behalf of 14 local authorities, and two other pieces of research released this week suggest there is a long way to go.
The study found the impact of integrated children's services on children in care, pupils with autism and truants was mentioned less frequently when local authority managers were interviewed.
"Few managers were able to describe the outcomes they had targeted or expected for the three key groups of children and young people," it says.
Where improvements were noted, they were usually unquantifiable, prompting the authors to say data collection and IT systems were "not yet fit for purpose".
Meanwhile, an ICM poll for the Guardian showed 56 per cent of heads thought it was "unacceptable" for schools to have more of a social services role, with 45 per cent saying they would feel the same even if they had more funds.
NFER's annual survey of trends in education revealed that only 27 per cent of secondary and 41 per cent of primary heads rated their schools' accessibility to social services support as excellent or good.
And while the situation had improved on the previous year, 38 per cent of primaries and 26 per cent of secondaries had still not been consulted over their local children and young people's plan.
John Dunford, the Association of School and College Leaders' general secretary, said: "In most parts of the country, we have yet to see the benefits of integrating children's services that heads were promised."