John Craig, who has carried out extensive research into the extended schools programme, was responding to the first detailed evaluation of it by researchers from the universities of Manchester and Newcastle.
The evaluation warned of 'strains' on school leadership teams who could be distracted from their 'core business' of promoting achievement.
Mr Craig said, 'Leading an extended school is a job of a qualitatively different kind to leading schools. Headteachers have not been prepared for the complexity of running an organisation that has to cross all these areas of children's services or of engaging such a range of professionals. They are making decisions that are increasingly locally significant. So the kind of services they decide to provide is actually a public issue. It's very easy for them to be drawn into local politics and they are not used to this public community role.'
The Evaluation of the Full Service Extended Schools Project: End of First Year Report found that in the long-term, the costs of the initiative could be outweighed by benefits for society in later years. While there was no firm evidence of the programme's 'effectiveness', the researchers found examples of greater pupil engagement, improved educational attainment and growing trust and support between families and schools.
Professor Alan Dyson of Manchester University's School of Education, one of the authors, stressed that while the study looked at 22 full service schools, there was likely in future to be 'a much greater emphasis on groups of schools making some sort of community offer rather than having an all-singing, all dancing full-service extended school'.
He said that the research had underlined the need for schools to exercise caution 'so that they do not overload existing senior management teams'. He added, 'They should distribute tasks or appoint a co-ordinator.'
The report revealed that some schools were concerned that developing childcare was distracting them from 'their core role of enhancing pupil learning'. Some local authorities felt the use of a private childcare provider 'led to a lack of control over provision, which was therefore harder to link with other FSES (full service extended schools) needs'.
The researchers said that they found no evidence of a threat to existing childcare provision from FSES provision, but that they had only spoken to FSES personnel and not private providers.
The report also delved into the issue of governance over schools. It said that if extended schools are 'to engage in the family and community agendas only with a view to their core business of enhancing children's learning, then it makes sense for their strategies to be led, developed and overseen internally. The school's community strategy becomes a sub-set of its teaching and learning strategy and is rightly the responsibility of heads and governors.
'If, on the other hand, the purposes of interventions reach beyond the school's core business, the case for leadership and governance being exercised beyond the school becomes much stronger.'
The report can be downloaded at www.dfes.gov.uk/research/ data/uploadfiles/RR680.pdf.
