🛡 Index of difficulty

= how difficult a task is independent from the input device

Formulas

🖱 Fitts Law

$ID:$ index of difficulty in bits $D:$ target distance $W:$ target width ==$ID={\log }_2(1+\frac{D}{W}))$==

🚗 Steering law

$ID:$ index of difficulty in bits $D:$ target distance $W:$ target width ==$ID=\frac{D}{W}$==

🔗 Links

🖱 Fitts Law