to the students themselves, to their colleagues, to parents and to policy makers. Progress reports provide information about

• The teacher's performance standards and criteria for evaluation.

• A student's progress from marking period to marking period and form year to year.

• A student's progress in mastering the science curriculum.

• A student's achievement measured against standards-based criteria.

[See System Standards A and B]

Each of these issues requires a different kind of information and a different mode of assessment.

Especially challenging for teachers is communicating to parents and policy makers the new methods of gathering information that are gaining acceptance in schools. Parents and policy makers need to be reassured that the newer methods are not only as good as, but better than, those used when they were in school. Thus, in developing plans for assessment strategies to compile evidence of student achievement, teachers demonstrate that alternative forms of data collection and methods of interpreting them are as valid and reliable as the familiar short-answer test.

The purported objectivity of short-answer tests is so highly valued that newer modes of assessment such as portfolios, performances, and essays that rely on apparently more subjective scoring methods are less trusted by people who are not professional educators. Overcoming this lack of trust requires that teachers use assessment plans for monitoring student progress and for grading. Clearly relating assessment tasks and products of student work to the valued goals of science education is integral to assessment plans. Equally important is that the plans have explicit criteria for judging the quality of students' work that policy makers and parents can understand.

[See Professional Development Standards B and C]

Master teachers engage in practical inquiry of their own teaching to identify conditions that promote student learning and to understand why certain practices are effective. The teacher as a researcher engages in assessment activities that are similar to scientific inquiries when collecting data to answer questions about effective teaching practices. Engaging in classroom research means that teachers develop assessment plans that involve collecting data about students' opportunities to learn as well as their achievement.

[See System Standards A and B]

Science assessments conducted by district, state, and national authorities serve similar purposes and are distinguished primarily by scale—that is, by the number of students, teachers, or schools on which data are collected.

Assessments may be conducted by authorities external to the classroom for the purposes of

• Formulating policy.

• Monitoring the effects of policies.

• Enforcing compliance with policies.