Teachers' use of curriculum to support students in writing scientific arguments to explain phenomena

The role of the teacher is essential for students' successful engagement in scientific inquiry practices. This study focuses on teachers' use of an 8-week chemistry curriculum that explicitly supports students in one particular inquiry practice, the construction of scientific arguments to explain phenomena in which students justify their claims using evidence and reasoning. Participants included 6 teachers and 568 students. Videotapes, teacher questionnaires, and student pre- and posttests were analyzed to develop case studies that characterized the support the teachers provided their students for scientific argumentation and subsequent student learning. Patterns from the case studies suggest that one particular instructional practice, the way teachers defined scientific argumentation, characterized teachers' support and influenced the other practices they used in their classrooms. In some cases, the teachers' definitions of scientific argumentation did not align with the intended learning goal in the curriculum materials. These teachers' greater simplification of this complex inquiry practice resulted in decreased learning gains in terms of students' ability to write scientific arguments to explain phenomena using appropriate evidence and reasoning. Educative curriculum materials can have a positive impact on teachers' classroom support for scientific argumentation, but how the teachers use these materials influences student learning. © 2008 Wiley Periodicals, Inc. Sci Ed93: 233–268, 2009