<p>This study investigates the perceptions of in-service science teachers in Korea regarding the reconceptualized FRA-to-NOS (RFN) by comparing these perceptions with findings from previous studies. The RFN Questionnaire, developed by Kaya et al. (2019), includes 70 questions divided into six sections. Data were collected from 12 in-service science teachers using this questionnaire. The data were analyzed using Excel to count the number of respondents and calculate the percentage for each response option. Results from the 5-point Likert scale RFN Questionnaire indicated that Korean science teachers demonstrated a good understanding of RFN perspectives for 55 out of 70 questions. Specifically, teachers showed a solid grasp of the RFN perspective in the “Aims and Values” and “Socio-Institutional Aspects” categories, but there was less understanding regarding the “Scientific Method” category. In-depth interviews revealed confusion regarding the 5-point Likert scale and the interpretation of items in the RFN Questionnaire. To address this issue, the teachers’ perceptions were re-examined with a modified 4-option Likert scale, resulting in a change in response patterns for six out of 70 questions. The findings confirm that the modified 4-option Likert scale more effectively measures science teachers’ perceptions of RFN. This study highlights differences in the perceptions of science teachers in Korea compared to those in other countries, along with common misunderstandings. The results also provide valuable insights for informing teacher education focused on the nature of science.</p>