This App has been designed to demonstrate Fitts' Law - also referred to as the speed-accuracy trade-off i.e. when moving between targets, speed and/or accuracy must be sacrificed for greater distances and smaller targets. The app has been designed primarily for research and teaching purposes.
Button widths and distances will vary depending on screen size, however the ratios are based on:
"Fitts P. M. (1954). The information capacity of the human motor system in controlling the amplitude of movement. Journal of Experimental Psychology. 47(6):381-391".
There are 16 possible combinations with index difficulty ratings between 1-7 as per Fitts (1954).
For each test, select the desired button size and distance between buttons - the resultant index difficulty will be displayed prior to the test. During the test, two buttons will be presented on the screen in the chosen dimensions. Using your mouse or only one finger of one hand (for touch screens), click/tap the buttons in an alternating sequence as quickly as possible for 10 seconds. You should notice that the greater the distance between the buttons and the smaller the buttons are, the less clicks/taps you will achieve during the 10 seconds and/or with reduced accuracy.
Note: if using a touch screen, this test is best suited for use with a stylus pen i.e. if you have large fingers, take care to only contact the screen within the borders of the button. Pressing down within the button but lifting up outside of the button will not register as an accurate press. Importantly, be careful of your screen if using a stylus, impacts may cause damage!
If you would like more information regarding dimensions etc, you can email me at firstname.lastname@example.org