Through participation in the NACL, leadership teams develop the knowledge and skills to lead improvement in their science program. The NACL program and the work of the teams back home is based on the following guiding principles:

• The National Science Education Standards present a vision of effective science education. To realize this vision, school- and district-based leaders need an increasingly wide range of knowledge and skills, which comes from research, reflective practice, and the expertise of other practitioners.
• A professional learning community is the cornerstone of sustainable curriculum implementation and focuses on a collective sense of responsibility for the learning of both students and adults in a school community.
• Curriculum can transform the professional practice and thinking of teachers. The implementation of standards-based, inquiry-oriented instructional materials, combined with sustainable professional development, can have a significant impact on teaching science and student learning.
• Leadership for curriculum reform is a shared process that includes understanding adult learning, accommodating the challenges of change, building relationships, and facilitating groups.
• The content and pedagogy of professional development must be designed through reflective practice to transform teachers' knowledge and beliefs about learning and teaching.