<![CDATA[This study aims to describe the implementation of an ethnophysics-based guided inquiry learning model on tempe fermentation and to analyze the improvement of students' conceptual understanding of heat. The study employed a mixed methods design with a concurrent triangulation strategy. The sample consisted of 64 eleventh-grade students at SMA GIKI 2 Surabaya: class XI IPA 1 as the experimental group (n = 33) and XI IPA 2 as the control group (n = 31), selected through purposive sampling. Quantitative data were collected through observation sheets and conceptual understanding tests (pretest and posttest), while qualitative data were obtained through semi-structured interviews. The results showed that learning implementation reached 94.74% (very good category), indicating that all guided inquiry syntaxes (problem orientation, formulating hypotheses, designing procedures, collecting data, analyzing data, and drawing conclusions) were implemented optimally. The experimental group's conceptual understanding improved significantly with an average N-Gain of 0.71 (high), while the control group reached only 0.28 (low). The highest improvement occurred in interpreting, classifying, and summarizing indicators (N-Gain = 1.00), while the lowest was in inferring (N-Gain = 0.33). Triangulation of observation, test, and interview data confirmed that the ethnophysics-based guided inquiry model on tempe fermentation effectively improves students' conceptual understanding of heat. This study implies the availability of an innovative learning model integrating local wisdom of tempe fermentation as a teacher reference for improving physics learning quality while fostering appreciation for Indonesian local culture.]]>
