Teachers' Understanding of the Nature of Science and Classroom Practice: Factors That Facilitate or Impede the Relationship.

The purpose of this multiple case study was to investigate the relationship of teachers' understanding of the nature of science and classroom practice and to delineate factors that facilitate or impede a relationship. Five high school biology teachers, ranging in experience from 2 to 15 years, comprised the sample for this investigation. During one full academic year, multiple data sources were collected and included classroom observations, open-ended questionnaires, semistructured and structured interviews, and instructional plans and materials. In addition, students in each of the teachers' classrooms were interviewed with respect to their understanding of the nature of science. Using analytical induction, multiple data sources were analyzed independently and together to triangulate data while constructing teacher profiles. The results indicated that teachers' conceptions of science do not necessarily influence classroom practice. Of critical importance were teachers' level of experience, intentions, and perceptions of students. The results have importnat implications for teacher education as well as the successful implementation of current reforms. © 1999 John Wiley & Sons, Inc. J Res Sci Teach 36: 916–929, 1999