The Effects of Keyboard Layout and Size on Smartphone Typing Performance

Abstract

Usability and typing performance on a smartphone with two unique QWERTY keyboard layouts (standard vs. curved) on two phone sizes (4.0-inch vs. 5.5-inch displays) was investigated in this study. The effect of hand posture was also investigated (one- vs. two-thumbs). Results show users typed the slowest when using one thumb with the curved keyboard on the small phone (15 WPM), and the fastest when using two thumbs with the standard keyboard on the large phone (24 WPM). Typing performance with the curved keyboard on the large phone size (19 WPM) did not differ between typing with one thumb using the standard keyboard on the large or small phone, or with two thumbs using the standard keyboard on the small phone. Error rates were higher when using the curved keyboard, regardless of phone size. Subjectively, the curved keyboard was rated inferior for both phone sizes in comparison to the standard layout.

Which Thumb, the Left or Right, Touches the Letter Keys on a Smartphone QWERTY Soft Keyboard during Two-Thumb Key Entry?

“…Thus, users have naturally been trained and accustomed to using their left hand relatively more often for typing letter keys on the physical QWERTY keyboard, as illustrated in Figure 5. In considering that QWERTY keyboard layouts of mechanical typewriters were passed down to QWERTY keyboard layouts of computers and furthermore smartphones [21,30,31], it was not surprising to see this finding in the present study-the keys that were relatively more often touched by the left thumb in the present study were almost identical to the keys that were specified to be pressed by the left hand in Figure 5, except the key B. Most keys were touched statistically more often using the thumbs that were relatively closer to the keys in the distance, excluding the keys G and V in the middle area.…”