Usability of one-handed interaction methods for handheld projection-based augmented reality

With the advent of the portable projector (also embeddable in a smart phone), projection-based augmented reality (AR) will be an attractive form of AR as the augmentation is made directly in the real space (instead of on the video screen). Several interaction methods for such "Procam"-based projection AR systems have been developed, but their comparative usability has not been studied in depth. In this paper, we compared the usability of four representative interaction methods, as applied to the menu selection task, for the handheld projection-based AR. In particular, we explored the possibility of using just one hand for enhanced convenience and mobility. As such, the four menu selection methods chosen for the study were formed by combinations of two types of cursor control (projector cursor vs. on-device touch screen), and two types of object selection (explicit click vs. crossing), all feasible with only one hand. Other considerations included the need for maintaining the stability of the handheld projector and effectively taking advantage of the smart phone as the interaction device. Experimental results have shown that the menu selection task was the most efficient, usable and preferred when the projector cursor with the crossing widget was used. Furthermore, the task performance was not statistically different among using the dominant, non-dominant hand and even both hands.