Try it yourself. Choose your input device and click 'Begin'.
Message here
Saving...
Click the red square to start
0/5 clicks :
Difficulty _
Small, distant buttons take longer to click on than large, close buttons. This relationship is expressed by Fitts’s law:
T = a + b log2(D/W + 1)
Where T is time, a and b are experimentally determined constants, D is distance to the target and W is the width of the target.