The impact of leadership on school effectiveness has been the central focus of a number of studies and part of the effective schools movement. Good relationship between the leadership of the principal and student outcomes is always expected within the school organization, leadership affects the ways teachers perceive their work environment, and it ultimately produces a measurable gain in student achievement. Effective elementary school could be easily distinguished from less effective ones. Most of the factors that contribute to effectiveness are related to "purposeful leadership". It could be said that, purposeful leadership happens when the leader understands the needs of the school and is actively involved in school's work without exerting total control over the staff. "Educational leadership today requires skills, knowledge, and attitude that are remarkably different than those required only a few decades ago. The leader should be the facilitator of school improvement and the keeper of the collective covenant, rather than the custodian of the status quo".