Differences in performance between both hands were observed and studied in various areas, but not during interaction with mobile devices such as smartphones. Previous work showed that one handed Back-of-Device interaction with mobile devices is desired. One-handed interaction is sometimes unavoidable, both for preferred hand and non-preferred hand. In this project, we will study the difference in performance between preferred and non-preferred hands during one-handed mobile interaction at the back of the device. We will compare their performance by comparing their speed and error rate in three tasks: target acquisition, linear steering and circular steering. We will analyze the impact of hand used, task type, motion direction and task difficulty (target width and amplitude in target acquisition task, and tunnel length and tunnel width in two steering tasks) on participants’ performance. During our experiment, we will also collect the IMU data of the device in case we need to analyze the correlation between the hand used and the overall movement of the device. This registration presents our plan for the experimental procedure and statistical analysis prior to collecting the data.