How to position the cursor?: an exploration of absolute and relative cursor positioning for back-of-device input

Observational studies indicate that most people use one hand to interact with their mobile devices. Interaction on the back-of-devices (BoD) has been proposed to enhance one-handed input for various tasks, including selection and gesturing. However, we do not possess a good understanding of some fundamental issues related to one-handed BoD input. In this paper, we attempt to fill this gap by conducting three studies. The first study explores suitable selection techniques; the second study investigates the performance and suitability of the two main modes of cursor movement: Relative and Absolute; and the last study examines solutions to the problem of reaching the lower part of the device. Our results indicate that for BoD interaction, relative input is more efficient and accurate for cursor positioning and target selection than absolute input. Based on these findings provide guidelines for designing BoD interactions for mobile devices.