Abstract:
Mobile phones have become a vital part of our everyday activities for personal, business and educational purposes. A lot of
interaction with the mobile phone is a via text input. This research presents an empirical evaluation of the effectiveness of the
touchscreen and keypad interactive styles for text input on mobile phones. An experiment was setup to investigate any
differences between four mobile input styles: Touchscreen QWERTY, Touch screen Multi-press, Keypad QWERTY and
Keypad Multi-press. The research found no significant difference between the touchscreen keyboards. However, there was a
significant difference (p=0.016 at 95% confidence) between the physical keyboards. Keypad QWERTY was the fastest
(27.5WPM) while Keypad multi-press was the slowest (18.1WPM). Results from post-experiment questionnaires showed no
difference in learnability between the four methods but, differences occurred in error rate and efficiency. It is also shown that
results of our experiment are comparable to those presented by earlier research which developed a predictive model based on
Fitt‟s law.
