An Electronic Geometric Compass Approach to Tracking Geometric Constructions for Formative Assessment

Geometric construction is a key component of mathematics education worldwide, supporting the development of spatial reasoning, logical thinking, and geometric proof. Although dynamic geometry software such as GeoGebra and Cinderella has broadened opportunities for digital exploration, virtual compasses may lack the tactile realism and procedural clarity of traditional instruments, which may influence students’ understanding of the construction steps and underlying concepts. To address this issue, we developed an electronic geometric compass that replicates the structure and function of a physical compass while capturing detailed process data. The device replaces the pencil with an electronic pen and equips the needle with a position sensor, enabling both stroke data and needle coordinates to be recorded in InkML format. A nationwide study involving 100 Japanese upper-secondary students who completed 20 classical construction tasks demonstrated that the electronic geometric compass effectively captures learners’ strategies, hesitations, and trial-and-error behaviour. These findings highlight the potential of this hybrid analogue–digital tool to enhance formative assessment, provide deeper insight into learners’ geometric reasoning, and support the development of future automated evaluation and personalised feedback systems.