Ergonomic characteristics of gestures for front- and back-of-tablets interaction with grasping hands

The thumb and the fingers have different flexibility, and thus, gestures performed on the back of a held tablet are suggested to be different from ones performed on the touchscreen with the thumb of grasping hands. APIs for back-of-device gesture detection should consider that difference. In a user study, we recorded vectors for the four most common touch gestures. We found that drag, swipe, and press gestures are significantly differently when executed on the back versus on the front side of a held tablet. Corresponding values are provided that may be used to define gesture detection thresholds for back-of-tablet interaction.