Junior high school students' understanding of the nature of science. Objective: The purpose of this research is to explore the junior high school students' understanding of nature of science (NOS). Methods: The survey in this research was conducted in 8th grade as many as 80 students from three schools in East Prabumulih Sub-District, South Sumatera Province, Indonesia, which was determined by stratified random sampling technique. Students' understanding of 7 aspects of NOS was measured using a questionnaire containing 35 items consisting of 4 Likert scale statements (scale 1-5) and 1 question open-ended responses to each aspect of NOS. Findings: The results showed that students' understanding of NOS is still inadequate. The students' understanding of NOS that inadequate shown through by the small percentage of the informed view category on all aspects of the NOS measured, both Likert scale items and open-ended responses. Conclusion: These findings emphasize the need for learning to improve understanding of NOS for students.

As part of the scientific literacy component, the nature of science (NOS) contributes to the process of forming students with scientific literacy. This study aims to develop students’ NOS understanding through explicit-reflective learning with socio-scientific issues (SSI) context. The quasi-experimental research method with the non-equivalent pretest-posttest control-group design was used in this study. A total of 45 students in seventh grade from a private junior high school in Prabumulih participated in this study and were grouped into 24 students in experimental class and 21 students in comparison class. Essay questions are used as the instruments in pre- and post-learning to measure students’ understanding five aspects of NOS, which are subjective, tentative, empirical, observation, and social and cultural. The results show that the percentage of students in the experimental class who display an increase in NOS understanding is greater than the students in the comparison class. This study shows that explicit-reflective learning with the SSI context could be used to develop students’ understanding of NOS.