Performance Envelopes of in-Air Direct and Smartwatch Indirect Control for Head-Mounted Augmented Reality

The scarcity of established input methods for augmented reality (AR) head-mounted displays (HMD) motivates us to investigate the performance envelopes of two easily realisable solutions: indirect cursor control via a smartwatch and direct control by in-air touch. Indirect cursor control via a smartwatch has not been previously investigated for AR HMDs. We evaluate these two techniques for carrying out three fundamental user interface actions: target acquisition, goal crossing, and circular steering. We find that in-air is faster than smartwatch (p <; 0.001) for target acquisition and circular steering. We observe, however, that in-air selection can lead to discomfort after extended use and suggest that smartwatch control offers a complementary alternative.