This study aimed to assess middle school students’ understanding of scientific units and propose instructional improvement strategies to enhance their comprehension of unit concepts. To this end, basic and in-depth surveys were conducted in 2024 wit...
This study aimed to assess middle school students’ understanding of scientific units and propose instructional improvement strategies to enhance their comprehension of unit concepts. To this end, basic and in-depth surveys were conducted in 2024 with third-year middle school students to investigate their understanding of scientific unit concepts. In addition, semi-structured interviews were carried out with selected respondents to qualitatively examine their cognitive characteristics. Through these interviews, students' actual difficulties in understanding unit concepts, intuitive misconceptions, and limitations in verbal expression were identified, providing foundational data for improving instruction. In 2025, an experimental lesson on the electricity unit (Ohm's Law) was designed and implemented for second-year middle school students, followed by pre- and post-lesson surveys to quantitatively analyze changes in their understanding of scientific units. The experimental lesson focused on the concepts of voltage, current, and resistance and included various elements such as unit calculation, unit conversion, and understanding of the Ohm’s Law equation. The analysis of changes in correct answer rates revealed that the experiment-based lessons, which emphasized the connection among concepts, symbols, and formulas, were effective in improving students’ understanding of unit concepts. Specifically, the correct answer rate increased by 24.0 percentage points in the Ohm’s Law calculation item and by 8.7 percentage points in the unit conversion item, suggesting that experience-based instruction contributes to the internalization of abstract concepts. Furthermore, students’ inquiry worksheets—comprising graphical representations and written responses after the experimental lesson—were analyzed to explore their conceptual application processes and patterns of reasoning. The results revealed various cognitive errors, including misconceptions that treat units as mere symbols or calculation tools, misunderstandings about relationships among units, and formal imitation of experimental outcomes. This integrated approach, combining qualitative and quantitative methods, provides a multidimensional perspective on the process of forming unit concepts and offers foundational insights for improving the effectiveness of science education in middle school.
Keywords: scientific units, unit concepts, Ohm’s Law, electrical units, unit understanding, unit conversion, experimental lesson, conceptual change, inquiry worksheet, student interviews, misconception analysis, middle school science education