AR-Classroom: Usability of AR Educational Technology for Learning Rotations Using Three-Dimensional Matrix Algebra.

The AR-Classroom application utilizes augmented reality technology (AR) to make the three-dimensional (3D) rotations underlying matrix algebra visible and interactive. The AR-Classroom has physical and virtual versions, where users can perform rotations using a physical LEGO model or by manipulating the application's x, y, and z axes sliders to rotate a virtual model. Both versions provide 3D matrices, color-coded axes lines, and a green wireframe superimposed onto a LEGO model to represent transformations. To ensure that the AR-Classroom makes learning 3D matrix algebra more engaging and accessible, two usability tests were used to evaluate the discoverability and usability of the app. The benchmark test assessed usability in the AR-Classroom's original format, and recommendations were made to improve the app., such as adding additional instructions on model set-up, restructuring, and updating the instructions, and turning the 'visualization type 'function into a button to make it easier to find. After the improvements, the updated usability test assessed usability again so that the impact of the modifications could be evaluated. Participants followed similar procedures in both the benchmark $(\mathrm{N}=12)$ and updated usability $(\mathrm{N}=12)$ tests. Participants completed a pre-test assessing their math abilities and confidence, watched a video on geometric transformations, and then were randomly assigned to interact with either the physical or virtual version of the app. While interacting with the app, participants were given tasks to complete while thinking out loud and provided an ease-of-use rating from $1=\text{very}$ easy to $7=\text{very}$ difficult (i.e., SEQ score). Once done interacting with the app, participants completed a post-test assessing their math abilities and confidence and provided feedback on their overall experience with the app (i.e., SUS). A thematic analysis was conducted after each test to identify and code themes in interaction and compare findings from the benchmark and updated tests. Results indicated that after changes were made to the app, the usability of both versions significantly improved: users were better able to set up the space shuttle model, effectively utilize the in-app instructions, and quickly access all of the app's features. Findings from the updated usability test contribute to enhancing the AR-Classroom app and further its use in higher education classrooms for learning matrix algebra.