There is a widespread misconception that all great headteachers are domineering, charismatic figures who rule with a rod of iron and demand that their staff are either for or against them.
A classic example of this was the legendary Crazy Joe Clark of Jersey City in the United States, who stalked the corridors of his school, swinging a baseball bat and letting fly at pupils and teachers alike in order to get them into classrooms.
The good news is, it didn't work. In fact, the research findings on school leadership are very consistent and reveal a quite different picture of successful headteachers. Although they come in all shapes and sizes, a number of characteristics are found repeatedly among those whose performance is excellent.
First, they have a vision. One New York headteacher commented that "ten years ago, if I'd had a vision they'd have locked me up; now I can't get a job without one". But what "having a vision" actually means is that the heads have a clear picture in their mind of what they want their schools to be like.
It is notable that, in successful schools, the heads will always speak about their plans, their ideas for the future and their hopes for the school. In failing schools, by contrast, the talk tends to be about the external forces which are said to be responsible for the school's inadequacies.
Importantly, successful heads also possess the ability to communicate their vision to others. They will use all the planned and chance meetings which make up a head's day - morning staff briefings, contacts with parents and children - not just to pass on information but also as an opportunity to inspire and to learn. As the inspirational head Carole Evans says, "never walk past bad practice".
A vital ingredient for successful headship is that heads share leadership with their colleagues and are not afraid to devolve responsibility. They delegate not only through the formal hierarchy but also by responding positively to individual initiative and innovation and by allowing others to take the lead in some key areas, such as the drawing up of school policy on important themes. There is a conscious effort to empower others, both staff and pupils, and a culture which encourages people to make change happen rather than waiting anxiously for it to occur.
Successful heads develop their staff. Teachers are conscientious. If asked to choose between their own development and that of their pupils, they will almost invariably put the pupils first. Good heads redress this and encourage what Charles Handy calls "a proper selfishness". They recognise the truth of Elizabeth Cady Staunton's dictum that "self-development is a higher goal than self-sacrifice" and that effective professional development is central to the creation of an effective school.
Finally, heads think strategically. They don't simply respond to the many challenges that buffet any school but keep their eyes on their strategic goal of creating the kind of school which they can see in their "vision" . As one analyst put it, "managers set manageable goals and work towards them; leaders set unattainable goals - and achieve them".
The Government's conference last week gave a high profile to the importance of leadership. Its investment in headteacher training and the promise of a prestigious National College for School Leadership provide the first systematic support for those whose task is to transform our schools.