to the class. Each student maintains journal notes on this process. When a group is satisfied that their plan has progressed to the point where work can begin, the plan is presented to classmates. Written copies of the plan are distributed for written review, followed by a class seminar to discuss each research plan. On the basis of peer feedback, each group revises its research plan, recognizing that as the plan is implemented, it will require still further revisions. Each student in the class is responsible for reviewing the research plan of every group, including a written critique and recommendations for modifying the plan.
EXECUTING THE RESEARCH PLAN. During this phase of the extended investigation, students engage in an iterative process involving assembling and testing apparatus; designing and testing forms of data collection; developing and testing a data collection schedule; and collecting, organizing, and interpreting data.
DRAFTING THE RESEARCH REPORT. Based on the notes of individuals, the group prepares a written report, describing the research. That report also includes data that have been collected and preliminary analysis. Based on peer feedback, the groups modify their procedures and continue data collection. When a group is convinced that the data-collection method is working and the data are reasonably consistent, they analyze the data and draw conclusions.
After a seminar at which the research group presents its data, the analysis, and conclusions, the group prepares a first draft of the research report. This draft is circulated to classmates for preparation of individual critiques. This feedback is used by the group to prepare its final report.
ASSESSING INDIVIDUAL STUDENT ACHIEVEMENT. While the class is engaged in the extended investigation, the teacher observes each student's performance as the student makes presentations to the class, interacts with peers, and uses computers and laboratory apparatus. In addition, the teacher has products of the individual student's work, as well as group work, including draft research questions, critiques of other student work, and the individual student's research notebook. Those observations of student performance and work products are a rich source of data from which the teacher can make inferences about each student's understanding of scientific ideas and the nature of scientific inquiry. For instance, in the context of planning the inquiry, students pose questions for investigation. Their justifications for why the question is a scientific one provide evidence from which to infer the extent and quality of their understanding of the nature of science, understanding of the natural world, understanding of the life, physical, and earth sciences, as well as the quality and extent of their scientific knowledge and their capacity to reason scientifically.
Evidence for the quality of a student's ability to reason scientifically comes from the rationale for the student's own research question and from the line of reasoning used to progress from patterns in the collected data to the conclusions. In the first instance, the student distills a research question from an understanding of scientific