Supplementary material for "Teaching multimodal interaction in cars to first-time users"

This study explores three variations of a proactive method to teach multimodal gaze and gesture interactions to first-time users in the scenario of an SAE level 5 automated vehicle. The three variations differed in size, placement on the screen, and whether active user input was required to receive additional information. The results of a user study involving the gesture control prototype in a driving simulator (N=30) show that the greatest variation was more effective in teaching, caused by significant differences in visibility ratings (p<0.001), size (p<0.001) and duration (p=0.001) of the pop-ups. The results show no correlation between the measured effectiveness and the preference for a specific variation. Across all variations, participants are positive toward receiving proactive teaching from their car to learn new features. We conclude that proactively teaching users novel interaction methods has the potential to improve the user experience in future vehicles.