Usability evaluation of dynamic geometry software through eye tracking and communication breakdown analysis

Yağmur, Serap
The use of information technology in mathematics education has become popular due to the increasing availability of software applications designed for constructing mathematical representations. In this study, we conducted a usability evaluation of GeoGebra, which is a commonly used math education tool that provides dynamic geometry, spreadsheet and algebra features. The study consists of three usability experiments. In the first experiment, an eye tracking study was conducted where individual participants performed basic geometric constructions by using the basic features of GeoGebra and a similar, well-known math education software called Geometer’s Sketchpad. Constructions completed in each interface were compared in terms of task completion times, accuracy and fixation durations in an effort to identify usability issues. According to results, there are no significant differences between GeoGebra and Geometer’s Sketchpad in terms of usability measures. In the second study, pairs of students collaboratively attempted more complex geometric constructions in the GeoGebra environment by using a mouse and a touch screen interface. The aim of the second experiment was to observe how different interfaces would influence the use of the GeoGebra tool in an ecologically more realistic setting. We hypothesized that the touch screen interface would help students with the geometry tasks as it resembles the familiar pen&paper based interaction with mathematical representations. Episodes where participants experienced breakdowns during their collaboration due to system usability issues were identified and analyzed with qualitative methods. Contrary to our expectation, the results indicated that participants experienced more breakdowns while using the touchscreen interface, due to the inadequate support GeoGebra provides for touch-based gestures. Finally, an eye tracking study was conducted on the mobile version of GeoGebra. Our findings suggest that the mobile version primarily replaced the function of the mouse in the desktop version with the finger, and did not take advantage of the gestures supported by the multi-touch screens of new generation tablet computers. Based on the empirical findings of the study, design ideas for improving the usability of the existing GeoGebra desktop and touch-based mobile interfaces are proposed.