A comparison of two input methods for keypads on mobile devices

Two mobile device text entry methods were evaluated. The well-known Multitap method was compared to our RollPad method on a new device utilizing a tactile touchpad in place of a keypad. RollPad was well liked by participants. KSPC (keystrokes per character) was significantly lower: 1.42 compared to 2.13 with Multitap. However, no significant difference was found in error rates or entry speed, with speed measured at about 7.3 wpm for both methods.