Investigation into Touch Performance on a QWERTY Soft Keyboard on a Smartphone: Touch Time, Accuracy, and Satisfaction in Two-Thumb Key Entry

This research aims to examine touch performance and user-satisfaction depending on key location in a QWERTY soft keyboard during two-thumb key entry on a smartphone. Thirty-three college students who were smartphone users were recruited, and an experimental program was implemented to measure their task completion time, the number of touch errors, and user-satisfaction during key entry. The QWERTY layout was split into 15 zones to assign absolute positions for reliable statistical analysis. The results showed that the zones with significantly longer task completion times were observed more prevalently in the zones in the periphery (p < 0.0001). In addition, relatively higher subjective satisfaction ratings were found in the zones in the center area of the QWERTY layout (p < 0.0001). It seemed that both of the results were improved in the zones that participants could immediately see without moving the thumbs, before touch interaction. Meanwhile, touch error frequencies failed to show statistical significance among the zones (p = 0.3195).