In the vision of science education portrayed by the Standards, effective teachers of science create an environment in which they and students work together as active learners. While students are engaged in learning about the natural world and the scientific principles needed to understand it, teachers are working with their colleagues to expand their knowledge about science teaching. To teach science as portrayed by the Standards, teachers must have theoretical and practical knowledge and abilities about science, learning, and science teaching.

The standards for science teaching are grounded in five assumptions.

• The vision of science education described by the Standards requires changes throughout the entire system.

• What students learn is greatly influenced by how they are taught.

• The actions of teachers are deeply influenced by their perceptions of science as an enterprise and as a subject to be taught and learned.

• Student understanding is actively constructed through individual and social processes.

• Actions of teachers are deeply influenced by their understanding of and relationships with students.

THE VISION OF SCIENCE EDUCATION DESCRIBED BY THE STANDARDS REQUIRES CHANGES THROUGHOUT THE ENTIRE SYSTEM. The educational system must act to sustain effective teaching. The routines, rewards, structures, and expectations of the system must endorse the vision of science teaching portrayed by the Standards. Teachers must be provided with resources, time, and opportunities to make change as described in the program and system standards. They must work within a framework that encourages their efforts.

The changes required in the educational system to support quality science teaching are major ones. Each component of the system will change at a different pace, and most changes will be incremental. Nonetheless, changes in teaching must begin before all of the systemic problems are solved.

WHAT STUDENTS LEARN IS GREATLY INFLUENCED BY HOW THEY ARE TAUGHT. The decisions about content and activities that teachers make, their interactions with students, the selection of assessments, the habits of mind that teacher

demonstrate and nurture among their students, and the attitudes conveyed wittingly and unwittingly all affect the knowledge, understanding, abilities, and attitudes that students develop.

[See Professional Development Standard A]

THE ACTIONS OF TEACHERS ARE DEEPLY INFLUENCED BY THEIR PERCEPTIONS OF SCIENCE AS AN ENTERPRISE AND AS A SUBJECT TO BE TAUGHT AND LEARNED. All teachers of science have implicit and explicit beliefs about science, learning, and teaching. Teachers can be effective guides for students learning science only if they have the opportunity to examine their own beliefs, as well as to develop an understanding of the tenets on which the Standards are based.