Such a leadership system appears to provide a supportive framework for professional accountability in which teachers feel more accountable to one another for their performance, unlike the United States form of administrative accountability, in which teachers are made accountable to the principal and others in supervisory positions. This differs from the United States where, for example, a teacher can apply to train as a principal or school head, and then apply for a position in a school. In Singapore, young teachers are continuously assessed for their leadership potential and given opportunities to demonstrate and learn by, for example, serving on committees, then being promoted to head of department at a relatively young age. Some are transferred to the ministry for a period.