Enhancing Gesture Typing on the T9 While Maintaining Standard Keyboard Layout
Gesture typing is a unique text entry paradigm on the touchscreen since it has good tactile feedback and is easy to use. Additionally, typing on the T9 keyboard can alleviate text input difficulties on small screen devices. However, many words contain consecutive letters that share the identical key on the T9 keyboard. For typing these words with gestures, users need to rely on the combination of tap typing and gesture typing. In this study, T9 with an enhanced key 1 and T9 with wiggle gestures were proposed to resolve the issues of interrupting gestures of swipe typing on the T9 while maintaining the standard keyboard layout. In comparison with gesture typing on conventional T9 in terms of performance and subjective feedback, T9 with an enhanced key 1 showed significant advantages over the other two T9 keyboards in almost all metrics according to the results collected from a user study. For instance, T9 with an enhanced key 1 was 25:7~ faster than conventional T9 and was also favored by the subjective ratings of all six NASA-TLX measures. As for T9 with wiggle gestures, it required higher learning costs and at least did not significantly degrade the performance of the T9 keyboard.