WhichHand: automatic recognition of a smartphone's position in the hand using a smartwatch

As mobile users often operate their devices with one enhancing one-handed interaction. In this paper, we present WhichHand, a system that 1) automatically detects which hand is holding a mobile phone and then 2) enhances user interfaces by adapting layouts to left-or right-handed use. For WhichHand, we utilize orientation sensors from a smartphone and a smartwatch. The relationship of sensor data between two mobile devices plays an important role in our recognition system. We evaluated WhichHand in a controlled study with 14 participants and conducted a user study with 10 participants to receive feedback. The accuracy of over 97% and early feedback on WhichHand provide useful insights on the design for one-handed interaction.