Improving touchscreen keyboards: Design issues and a comparison with other devices

Abstract

The study explored touchscreen keyboards using high precision touchscreen strategies. Phase one evaluated three possible monitor positions: 30°, 45°, and 75° from horizontal. Results indicate that the 75° angle, approximately the standard monitor position, resulted in more fatigue and lower preference ratings. Phase two collected touch bias and key size data for the 30° angle. Subjects consistently touched below targets, and touched to the left of targets on either side of the screen. Using these data, a touchscreen keyboard was designed. Phase three compared this keyboard with a mouse-activated keyboard, and the standard QWERTY keyboard for typing relatively short strings of 6,19, and 44 characters. Results indicate that users can type approximately 25 words/minute (wpm) with the touchscreen keyboard, compared to 17 wpm using the mouse, and 58 wpm when using the keyboard. Possible improvements to touchscreen keyboards are suggested. © 1991 Butterworth-Heinemann Ltd.