One-hand texting usability with iphone 5 touch-screen keyboard vertical position

We focus our research on how vertical position of Touchscreen QWERTY keyboard affects smartphone user’s text messaging performance in terms of usability, time to completion, ease of use, typo-error frequency and overall satisfaction from bottom, middle to top position. Two different smartphones were selected; Apple iPhone5 (iOS) and Samsung Galaxy III (Android). We asked participant typing three pre-selected text messages by one-hand thumb typing. The results showed the default position (bottom) was the least favorable position in terms of user performance and user experience with Apple iPhone5. Typo-error counts and text-messaging time showed no significant results, but showed a consistent pattern. Usefulness, easy of use, comfort, weight balance and satisfaction showed significant results from the middle and the top position. This result further suggests that Touchscreen QWERTY keyboard vertical position need to be repositioned either to the middle or to top position to improve user experience.