The data come from a task in which the goal is to move a computer mouse to a target on the screen as fast as possible. On 20 of the trials, the target was a small rectangle; on the other 20, the target was a large rectangle. Time to reach the target was recorded on each trial. The box plots of the two distributions are shown below. You can see that although there is some overlap in times, it generally took longer to move the mouse to the small target than to the large one.