Inclusion and management: participatory leadership of the school unit. A qualitative survey of primary school principals in Eastern Thessaloniki.

Over the time, the science of management has been influenced by the total of the social and economic developments, resulting in the formulation of three basic theories: the classical approach, the management through human relations and the modern management. Each of these three theories, focuses on different principles, which, with the proper treatment, can be applied to the field known as Educational Administration. The culture of each school unit is defined by the different values and attitudes of its members, while several times the change of culture is deemed necessary as it is a determining factor of the school climate, which in turn, affects the performance of both students and teachers. Any change in culture is a difficult and not an effortless process, whose successful outcome largely depends on the role played by the respective headteacher- leader. He is a key factor both in upgrading the quality and the effectiveness of education, as well as in fulfilling the goals associated with the students’ success.