Patients with spinal cord injuries can lose mobility in their arms and hands, and it is important to find the optimal design of a joystick that will enable them to perform tasks in the most efficient manner. An experiment was designed to compare two joystick designs. As a target moved across a computer screen, the patients were asked to use a joystick to follow the target with a cursor. Nine spinal cord injury patients participated in the study, and each patient tried out both joystick designs. DS 9.6.1 1 contains data on the mean error measurements that were calculated by aggregating the distances between the target and the cursor at a series of time points.