Influence Of “Decontextualized” And “Contextualized” “Explicit-Reflective” Instruction On High School Students' Understandings Of Nature Of Science

Nature of science(NOS)is an important objective for international science education for more than 100 years,having adequate views of NOS is of great significance to students.NOS has been advocated as a critical educational outcome by various science education reform documents and curriculum standards worldwide.“explicit-reflective” instructions in contexts has been suggested a effective way in improving students' conceptions of NOS.Studies show that,in China,NOS educations needs to be improved,students do not have a comprehensive understandings of science and most of them do not have informed views of NOS.The purpose of this qualitative study was to investigate the influence of decontextualized and contextualized “explicit-reflective” Instruction on high school students' understandings of NOS.The study emphasized 9 aspects of NOS:tentative?empirical?the distinction between theories and laws?the distinction between observation and inference?subjective?social and cultural embedding?creativity and imagination?scientific methods?scientific models/concepts.Participants were 15 students from senior one of a private middle school.Based on the “explicit-reflective” approach,we use 3 decontextualized activities and 3 contextualized chemical history in the instruction.An open-ended questionnaire(VNOS-C)in conjunction with semi-structured interviews?course video and reflective papers was used to assess participants' NOS views before and at the conclusion of the intervention.The results indicated that generally,students had inadequate understandings of NOS before the instruction,especially in the aspects of “the distinction between theories and laws”.At the end of instruction,students developed their views of NOS,the understanding of “the distinction between observation and inference ” improved most substantially,but the understanding of “scientific methods” and “scientific models/concepts” changed little?Using specific examples,this study showed the effective NOS instruction and its effectiveness,and provided examples of NOS instruction.It has great value to further improve students' views of NOS and carry out effective NOS instructions.