Headteachers who stay with their schools for longer than six years may be more effective in the job, new research suggests.
The link between successful schools and long-serving headteachers was the surprise finding of a study by Professor John Howson for the National College for School Leadership. The findings contradict the long-held view that heads are at their best between three and seven years into the job.
"This is the first study of its kind and it is significant that it has revealed a definite association between the length of headteacher service and Panda (performance and assessment) gradings," said Geoff Southworth, director of research at the leadership college.
Panda grades are based on information from inspection reports and test results, and rate a school's performance in comparison with similar schools. The best grade is A* and the worst E*.
Professor Howson, managing director of Education Data Surveys, found that the highest graded of the 2,500 primary and secondary schools he surveyed had the greatest percentage of heads with more than six years' service in the same post.
However, he points out that a statistical relationship does not necessarily mean that there is a causal link, a point reinforced by the national college.
"This is the bald evidence," said Mr Southworth. "More research will be required to establish the reasons for this link."
But the research chimes with another NCSL study, Enchanted Leaders, in which Ronnie Woods, head of the Cleaden Village junior school, on Tyneside, interviewed several very successful and long-serving heads.
"There are so many heads out there who have lived this job effectively and passionately for 10 or 20 years," said Mr Woods.
"You cannot claim to have got on top of the job until you have seen a cohort of children all the way through - and that takes at least seven years."
The view that managers have a sell-by date is a common one both inside and outside education. Large companies move senior staff every few years and the Army used to reassign commanding officers after three years. In Canada and the United States, school districts routinely move their principals around.
In the mid-1980s, researchers working for the Inner London Education Authority looked at 50 primary schools and found that long-serving heads were associated with less effective schools.
"Mid-term heads (three to seven years in post) were associated with the most effective schools," said Pam Sammons, one of the ILEA research team.
Professor Howson's research could now help to rekindle the debate about whether short-term contracts should be given to heads taking over challenging schools.
"In other parts of the world, headships are also offered as part of a short-term contract," said Peter Earley, of the London Leadership Centre, who has been monitoring a group of heads appointed in 1982.
When last questioned, those heads believed that the optimum tenure was between four and 10 years, although most of them had remained at their schools.
"Heads commented that, even if they wished to move, appointment panels would regard them as too old for the challenges of leadership," said Mr Earley. "Anyone over 50 was seen as too old to take on the challenge of a new school."
He said the NCSL research needed to be followed up, but he was not surprised by the results. "It's a different job today," he said. "Heads don't have time to go stale - they burn out or remain effective."
Professor Howson echoed that view. "The ILEA research led by Peter Mortimore came from a different world," he said. "The long-held belief may be too simplistic.
Clearly regeneration is possible, but how does it happen?"
Details of the research are available at the NCSL website. See www.ncsl.org.ukindex.cfm?pageid=kpool-archive-indexTelephone: 08701 0011155
* Do heads have a sell-by date? When are they at their best? TES letters (firstname.lastname@example.org) and NCSL (email@example.com) welcome readers'