Secondary School Physics Teachers' Conceptions of Scientific Evidence: A Collective Case Study

Open Access
Taylor, Joseph A
Graduate Program:
Curriculum and Instruction
Doctor of Philosophy
Document Type:
Date of Defense:
June 13, 2001
Committee Members:
  • Renata S Engel, Committee Member
  • Thomas M Dana, Committee Chair
  • Vincent Norman Lunetta, Committee Member
  • Carla Zembal Saul, Committee Member
  • Teacher Education
  • Science Teacher Education
  • Physics Teacher Education
  • Physics Education
Engaging secondary school students in inquiry-oriented tasks similar to the scholarly activities of scientists has been recommended as a way to improve scientific literacy. Two frequently recommended tasks are students’ design of original experiments and students’ evaluation of scientific evidence and conclusions. Science education scholars have suggested that teachers must possess well-developed conceptions of scientific evidence to guide students as they engage in these tasks. Yet, little is known about teachers’ conceptions of scientific evidence. The principal aim of this study, therefore, is to describe the nature of one prospective and two practicing physics teachers’ conceptions of scientific evidence. More specifically, the following research questions guided this study: (1) What types of issues related to the measurement reliability and experimental validity of scientific evidence do the participant-teachers think about when designing experiments? (2) When presented with hypothetical scenarios that describe unsound experimental procedures or poorly supported conclusions (or both), what concerns will the teacher-participants raise? And (3) When the teacher-participants’ responses to parallel research prompts are compared across protocols, what similarities and differences exist? The nature of the teacher-participants’ conceptions was derived from an analysis of data collected from research prompts such as interviews and hand written artifacts. In these research prompts, the teachers “thought aloud” while designing experiments and evaluating student–collected evidence presented in hypothetical classroom scenarios. The data from this study suggest that the three teachers, while contemplating the reliability and validity of scientific evidence, frequently used their conceptions of evidence in conjunction with specific subject matter conceptions. The data also indicates that the relationship between subject matter knowledge and conceptions of evidence was more pronounced for some conceptions of evidence (e.g., measurement validity, controlled experimentation, statistical significance) than for others. Suggestions for future research included conducting similar studies in other physics content areas as well as other scientific disciplines. Implications for science teacher education suggest that science and science methods courses encourage teachers to conduct original research and to construct and present evidence-based arguments from this research for peer review and critique.