Investigating Screen Shifting Techniques to Improve One-Handed Smartphone Usage

With increasingly large smartphones, it becomes more difficult to use these devices one-handed. Due to a large touchscreen, users can not reach across the whole screen using their thumb. In this paper, we investigate approaches to move the screen content in order to increase the reachability during one-handed use of large smartphones. In a first study, we compare three approaches based on back-of-device (BoD) interaction to move the screen content. We compare the most preferred BoD approach with direct touch on the front and Apple's Reachability feature. We show that direct touch enables faster target selection than the other approaches but does not allow to interact with large parts of the screen. While Reachability is faster compared to a BoD screen shift method, only the BoD approach makes the whole front screen accessible.