Headteachers must push their own values and demonstrate strength of personality as they attempt to turn around schools, according to new research which claims good leadership is the most effective way to achieve transformation.
Some 8,000 teachers took part in the three-year national study, The Impact of School Leadership on Pupil Outcomes, which is claimed to be the largest and most extensive of its type.
It set out to establish if there is a relationship between the role of headteachers and children's performance. The results look set to determine government spending on training for years to come.
The Department for Children, Schools and Families and National College for School Leadership study also repeats its interim finding that school leadership is second only to teaching as an influence on pupils' learning.
The researchers looked at schools where results had improved over five years and the qualities, strategies and skills of the heads involved. They concluded that leaders are essential if change is to be achieved - and that their actions and "virtues" are, in particular, key.
Many of the schools in the study went on to improve, leading the researchers to conclude that this shows leadership can be ingrained in schools' ethos.
"There are statistically significant empirical and qualitatively robust associations between heads' educational values, qualities and their strategic actions and improvement in school conditions leading to improvements in pupil outcomes," says the report, which is by academics from the University of Nottingham, the Institute of Education, part of the University of London, and the University of Toronto.
NCSL chief executive Steve Munby has said the report vindicates the organisation's Pounds 85 million funding for 2009-10 - up Pounds 4 million on this year.