Quantitative Data Collection by Secondary Science-Gifted Students: Repeated-measures in an Air-density Lesson

Abstract

This study has designed a lesson for secondary science-gifted students to estimate air density by comparing a fixed-volume container before and after depressurization, then analyzed the learners’ performance and interpretations. The lesson embodies NGSS Science and Engineering Practices such as collecting data under a range of conditions and considering limitations of data analysis and seeking to improve precision and accuracy of data. Students derived a theoretical value, measured volume, computed density, and interpreted results; evaluation criteria were drawn from post-lesson responses focusing on precision, accuracy, and uncertainty. Many students understood the theory and steps but struggled with small discrepancies in measurement and record-keeping, yielding unstable estimates. At the interpretation stage, distinctions between accuracy and precision were often unclear and justifications weak. The findings support a shift toward process-oriented, reflective evaluation that foregrounds uncertainty, precision, and accuracy, and includes repeated measurement, error diagnosis, and improvement planning.