This study assessed the influence of a 3-year professional development program on elementary teachers' views of nature of science (NOS), instructional practice to promote students' appropriate NOS views, and the influence of participants' instruction on elementary student NOS views. Using the VNOS-B and associated interviews the researchers tracked the changes in NOS views of teacher participants throughout the professional development program. The teachers participated in explicitreflective activities, embedded in a program that emphasized scientific inquiry and inquiry-based instruction, to help them improve their own elementary students' views of NOS. Elementary students were interviewed using the VNOS-D to track changes in their NOS views, using classroom observations to note teacher influences on student ideas. Analysis of the VNOS-B and VNOS-D showed that teachers and most grades of elementary students showed positive changes in their views of NOS. The teachers also improved in their science pedagogy, as evidenced by analysis of their teaching. Implications for teacher professional development programs are made. ß

This study assessed the influence of a reflective, explicit, activity-based approach to nature of science (NOS) instruction undertaken in the context of an elementary science methods course on pre-service teachers' views of some aspects of NOS. These aspects included the empirical, tentative, subjective (theory-laden), imaginative and creative, and social and cultural NOS. Two additional aspects were the distinction between observation and inference, and the functions of and relationship between scientific theories and laws. Participants were 25 undergraduate and 25 graduate preservice elementary teachers enrolled in two sections of the investigated course. An open-ended NOS questionnaire coupled with individual interviews was used to assess participants' NOS views before and at the conclusion of the course. The majority of participants held naive views of the target NOS aspects at the beginning of the study. During the first week of class, participants were engaged in specially designed activities that were coupled with explicit NOS instruction. Throughout the remainder of the course, participants were provided with structured opportunities to reflect on their views of the target NOS aspects. Postinstruction assessments indicated that participants made substantial gains in their views of some of the target NOS aspects. Less substantial gains were evident in the case of the subjective, and social and cultural NOS. The results of the present study support the effectiveness of explicit, reflective NOS instruction. Such instruction, nonetheless , might be rendered more effective when integrated within a conceptual change approach. on the importance of enhancing K-12 stu-dents' conceptions of NOS. However, the achievement of this long-espoused goal has been met with little success. Research has consistently shown that students' NOS views are not consis-JOURNAL

This study assessed, and identified factors in participants' learning ecologies that mediated, the effectiveness of an explicit reflective instructional approach that satisfied conditions for learning as conceptual change on preservice elementary teachers' views of nature of science (NOS). Participants were 28 undergraduate students enrolled in an elementary science methods course. A purposively selected focus group of six participants who showed differential growth in terms of their NOS views were closely followed throughout the study. The Views of Nature of Science Questionnaire‐Form B (VNOS–B) in conjunction with individual interviews was used to assess participants' views prior to and at the conclusion of the study. Other data sources included weekly reflection papers, exit interviews, and an instructor's log. Initially, the greater majority of participants held naïve views of NOS. Substantial and favorable changes in these views were evident as a result of the intervention. An examination of the development of the focus group participants' NOS views indicated that the effectiveness of the intervention was mediated by motivational, cognitive, and worldview factors. These were related to internalizing the importance and utility of teaching and learning about NOS, exhibiting a deep processing approach to learning, and viewing science and religion as two distinct rather than opposing enterprises. © 2004 Wiley Periodicals, Inc. Sci Ed 88:785–810, 2004

Although teacher educators have achieved some success in improving teachers' understanding of the nature of science (NOS), helping teachers teach NOS has proved a much greater challenge. Currently, there are few examples in the literature of teachers who effectively teach NOS, and fewer still that rely on student outcomes as a measure of teachers' effectiveness. Much remains to be understood regarding the sources, nature, and development of teachers' pedagogical content knowledge (PCK) in regard to NOS. Using S. Magnusson, J. Krajcik, and H. Borko's (1999) framework, we examined the PCK for NOS of three elementary teachers who have been successful in improving their students' understanding of NOS. We relied on interviews, questionnaires, classroom observations, and classroom artifacts collected over a 3-year period to characterize their PCK for NOS. Although each had robust knowledge of instructional strategies for teaching NOS, teachers lacked the requisite knowledge of assessment that would provide a feedback loop to support continued development of their knowledge of learners and lead to improvement in their teaching of NOS. Our findings highlight a need for professional development that focuses

This study examined the views, and the retention of these views, of 19 preservice elementary teachers as they learned about nature of science (NOS). The preservice teachers participated in a cohort group as they took a science methods course during which they received explicit reflective instruction in nature of science. Through Views of Nature of Science version B (VNOS‐B) surveys and interviews it was found that most preservice teachers held inadequate ideas of nature of science prior to instruction, but improved their views after one semester of instruction in the science methods course. However, 5 months after instruction, the graduate preservice teachers were again interviewed and it was found that several of the students reverted back to their earlier views. The results are interpreted through Perry's scheme, and implications and recommendations for elementary science teacher education are made. © 2005 Wiley Periodicals, Inc. J Res Sci Teach 43: 194–213, 2006