• Descriptions of the data-collection method.

• Descriptions of the method of data interpretation.

• Descriptions of the decisions to be made, including who will make the decisions and by what procedures.

ASSESSMENTS HAVE EXPLICITLY STATED PURPOSES. Conducting assessments is a resource-intensive activity. Routine assessments in the classroom place considerable demands on the time and intellectual resources of teachers and students. Large-scale assessments, such as those conducted by districts, states, and the federal government, require tremendous human and fiscal expenditures. Such resources should be expended only with the assurance that the decisions and actions that follow will increase the scientific literacy of the students—an assurance that can be made only if the purpose of the assessment is clear.

[See Teaching Standard F]

THE RELATIONSHIP BETWEEN THE DECISIONS AND THE DATA IS CLEAR. Assessments test assumptions about relationships among educational variables. For example, if the purpose is to decide if a school district's management system should be continued, assessment data might be collected about student achievement. This choice of assessment would be based on the following assumed relationship: the management system gives teachers responsibility for selecting the science programs, teachers have an incentive to implement effectively the programs they select, and effective implementation improves science achievement. The relationship between the decision to be made and the data to be collected is specified.

ASSESSMENT PROCEDURES NEED TO BE INTERNALLY CONSISTENT. For an assessment to be internally consistent, each component must be consistent with all others. A link of inferences must be established and reasonable alternative explanations eliminated. For example, in the district management example above, the relationship between the management system and student achievement is not adequately tested if student achievement is the only variable measured. The extent to which the management system increased teacher responsibility and led to changes in the science programs that could influence science achievement must also be measured.

Achievement and opportunity to learn science must be assessed.

• Achievement data collected focus on the science content that is most important for students to learn.

• Opportunity-to-learn data collected focus on the most powerful indicators.

• Equal attention must be given to the assessment of opportunity to learn and to the assessment of student achievement.

ACHIEVEMENT DATA COLLECTED FOCUS ON THE SCIENCE CONTENT THAT IS MOST IMPORTANT FOR STUDENTS TO LEARN. The content standards define the science all students will come to understand. They portray the outcomes of science education as rich and varied, encompassing

• The ability to inquire.

• Knowing and understanding scientific facts, concepts, principles, laws, and theories.