Students need the opportunity to evaluate and reflect on their own scientific understanding and ability. Before students can do this, they need to understand the goals for learning science. The ability to self-assess understanding is an essential tool for self-directed learning. Through self-reflection, students clarify ideas of what they are supposed to learn. They

begin to internalize the expectation that they can learn science. Developing self-assessment skills is an ongoing process throughout a student's school career, becoming increasingly more sophisticated and self-initiated as a student progresses.

Conversations among a teacher and students about assessment tasks and the teacher's evaluation of performance provide students with necessary information to assess their own work. In concert with opportunities to apply it to individual work and to the work of peers, that information contributes to the development of students' self-assessment skills. By developing these skills, students become able to take responsibility for their own learning.

Teachers have communicated their assessment practices, their standards for performance, and criteria for evaluation to students when students are able to

• Select a piece of their own work to provide evidence of understanding of a scientific concept, principle, or law—or their ability to conduct scientific inquiry.

• Explain orally, in writing, or through illustration how a work sample provides evidence of understanding.

• Critique a sample of their own work using the teacher's standards and criteria for quality.

• Critique the work of other students in constructive ways.

Involving students in the assessment process increases the responsibilities of the teacher. Teachers of science are the representatives of the scientific community in their classrooms; they represent a culture and a way of thinking that might be quite unfamiliar to students. As representatives, teachers are expected to model reflection, fostering a learning environment where students review each others' work, offer suggestions, and challenge mistakes in investigative processes, faulty reasoning, or poorly supported conclusions.

A teacher's formal and informal evaluations of student work should exemplify scientific practice in making judgments. The standards for judging the significance, soundness, and creativity of work in professional scientific work are complex, but they are not arbitrary. In the work of classroom learning and investigation, teachers represent the standards of practice of the scientific community. When teachers treat students as serious learners and serve as coaches rather than judges, students come to understand and apply standards of good scientific practice.

[See Teaching Standard C]

An essential responsibility of teachers is to report on student progress and achievement