Fitts's Law

I recently read “THE INFORMATION CAPACITY OF THE HUMAN MOTOR SYSTEM IN CONTROLLING THE AMPLITUDE OF MOVEMENT”, a Journal of Experimental Psychology paper by Paul M. Fitts. The paper describes a series of experiments which were conducted by Fitts and his results. The final result of which is known as Fitts’s Law. The time it takes to complete a movement, such as bushing a button, is equal to the time it takes to start/stop the device plus, the inherent speed of the device times the log of, one plus, the distance from the starting point to the target divided by the width of the target. Fitts’s law can be used to predict t the speed at which users can complete tasks on a given interface, thus helping to improve interface design. Basically, the bigger the button and the closer it is, the faster it can be pressed.