The implementation of the new standards of reform in science education necessitates intensive, life-long professional development of science teachers. In the past, conventional methods of conducting pre-service and in-service education and professional development have not always proved adequate for attaining such demanding goals. In-service workshops conducted all over the world have usually been too short and occasional to foster a change in teachers' classroom practice. Unfortunately many in-service projects were arranged as one-time events with very short lifetimes. In contrast, the current reform is characterized by the attention given to the professionalization of science teachers. Teaching science effectively in the classroom requires much more than just a straightforward implementation of the curriculum. One of the most promising and effective methods of attaining the goals of reform and of enhancing professional development is to develop leadership among science teachers.
In 1994, a National Center for Chemistry Teachers was established in the Department of Science Teaching. Until the end of the academic year 2000 I served as the head of this center. The overriding goal of this center was to develop a cohort of chemistry teacher-leaders (since than the center is operating under the leadership of Dr Rachel Mamlok-Naaman from the Chemistry Group). The idea was that these leading-teachers would eventually serve as agents for change namely will help in bringing about reform in chemistry education in Israel (both in its content as well as in the way it is taught). This initiative is part of the more comprehensive report (Tomorrow 98) that provides directions and actions to be taken in the professional development of science teachers in general, and in the development of leadership among science teachers in particular. For more details regarding the reform of professional development and about the national center (Hofstein & Even, (2001) .
Several programs aimed at developing leadership among chemistry teachers were initiated at the National Center for Chemistry Teachers.
The program for leading chemistry teachers, which was documented in the literature (Hofstein, Carmi, & Ben-Zvi (2003), was conducted over a period of two academic years, 450 hours in total. The program was designed around the following
3 components:
- Developing the teachers' understanding about the current trends of chemistry teaching and learning, which include both the content and the pedagogy of chemistry learning and teaching;
- Providing the teachers with opportunities to develop personally, professionally, and socially;
- Developing leadership and the ability to work with other chemistry teachers.
The program was assessed regarding the changes that the teachers underwent as a result of the leadership program. The assessment focused on three interrelated variables, namely:
- Developing the teachers' personal beliefs about themselves, about teaching chemistry, and about becoming a leader;
- Developing their professional behavior and activities in their chemistry classroom;
- Developing leadership skills and activities with other chemistry teachers in and outside their schools (social development).
With regard to the teachers' development at the personal level, it was found that as a result of their experiences, the teachers developed affectively. This development involved attending to feelings about the change process they underwent, about their feelings concerning the changes they underwent as chemistry teachers, and finally the increased confidence (over time) regarding the idea that they might become leaders in chemistry education. Evidence about the teachers' professional development was gathered from students' perceptions of the chemistry classroom environment as well as from the teachers' self-reports about the changes they underwent, which they applied in their daily classroom practice (in their own schools), and in out-of-school activities, namely in the science teachers' professional development centers. Finally, the teachers had many opportunities to enhance their social skills through collaboration and cooperation with their peers in the program, through working with the team of chemistry teachers in their own schools, and at a later stage in the professional development activities as tutors in professional development programs.
In addition, two courses were conducted in order to prepare school-based chemistry coordinators. In general, school-based coordinating chemistry teachers are expected to conduct the following activities: (1) plan the teaching and learning of the chemistry program, (2) expose the team of teachers to new curricula, new learning materials and new pedagogical interventions, (3) provide guidance and support to new teachers, and (4) act as a link between the teachers and the school management.
The program for coordinating chemistry teachers (Hofstein, Carmeli, & Shore, 2004) was designed so that 30 % of the program (224 hours) was devoted to the enhancement of content knowledge, 45 % to pedagogical content knowledge, and 25 % to the development of leadership abilities.