Learner-centered approaches to teaching and schooling require supportive policies for preparing effective educators. Moving from constructivist philosophy, psychology and epistemology to the characterization of constructivist teaching and learning environments presents a challenge. Constructivist philosophy does not dictate how one should teach; however, it does make it incumbent upon the teacher to deal with each learner as an individual, to value diversity of perspective, and to recognize that the learner's behavior is a direct reflection of his / her life experiences. Bandura (1977, 1986, 1995, 1997), Fullan (1993), and other self-efficacy researchers have concluded that the catalyst for educational reform is the individual teacher and that a teacher's behaviors, values, beliefs, and ambition to act may be enhanced or suppressed during student teaching.
The competence of natural sciences teachers should be perceived as a system every component of which is fundamental. Natural science literacy is a core that is basically acquired in comprehensive school (natural science education as a component of general education). An appropriate natural science qualification and the level of competence are obtained in higher school. A decisive moment is a permanent improvement of competence during practical activities of the teacher.