The effect of nature of science focused science content teaching through explicit-reflective teaching sequences on high school students' nature of science understanding.

The aim of this study is to develop a teaching sequence for teaching nature of science (NOS) focused science content with an explicit-reflective approach and to examine the effect of this teaching sequence on students? contemporary NOS understandings (such as humanistic features, history, and tentativeness of scientific knowledge). Furthermore, it is also aimed to help teachers learn the NOS and how teaching the NOS should be done within a scientific context.In this case study, 15 high school students at level III were selected with purposed sample method. NOS understandings emphasized in current science education reform documents such as 1) tentativeness, 2) empirical nature, 3) theory-laden nature, 4) creativity and imagination and 5) socio-cultural embeddedness of science were tried to teach students. Moreover, during the instruction it was also aimed to highlight the difference between the observation and inference, the relationship between theories and laws and their functions and development. The teaching sequence included teaching NOS understandings in the context of learning science content and teaching in the scope of learning as conceptual change approach by using an explicit-reflective approach. The instructional practices used in the study consisted of acquisitions, explicit-reflective activities and assessment.Applications of this teaching sequence are realized at four sessions on scientific world view, scientific methods of inquiry, nature of scientific enterprise and theories/laws while teaching chemical equilibrium subject. In these sessions; examples, explanations, demonstrations, historical vignettes which are including short sections of scientists life, inquiry based activities related with chemical equilibrium subject were used with an explicit-reflective approach.Implementation took 10 weeks as 3 hours per week for the 2nd semester of 2009-2010 education years. In this study, data were collected with a NOS questionnaire applied as pre and post test, semi-structured interviews conducted at the end of the instruction period, field notes and reflections at the end of all activities. The obtained data were analyzed qualitatively in accordance with grounded theory methodology. Additionally, a profile was formed for each student by means of scoring the answers to pre and post questionnaire.The results obtained from this study indicated that the explicit reflective teaching sequence was effective to make high school students develop more informed NOS understandings. This approach enabled the students to become more informed about the understandings related with tentative of scientific knowledge, experimental nature of science, the role of observations and inference, creativity and imagination in science. Additionally, the fact that students can relate NOS understandings with the chemical equilibrium on many aspects was understood from not only answers to questionnaire but also from interviews, written reflections and exams. During the instruction, students discussed the proper examples of the content to support their personal thoughts in the classroom environment.In the light of the findings obtained from this study, recommendations regarding the teaching of NOS embedded in science content subjects and future possible scientific investigations were submitted.