Haptic numbers: three haptic representation models for numbers on a touch screen phone

Systematic research on haptic stimuli is needed to create viable haptic feeling for user interface elements. There has been a lot of research with haptic user interface prototypes, but much less with haptic stimulus design. In this study we compared three haptic representation models with two representation rates for the numbers used in the phone number keypad layout. Haptic representations for the numbers were derived from Arabic and Roman numbers, and from the Location of the number button in the layout grid. Using a Nokia 5800 Express Music phone participants entered phone numbers blindly in the phone. The speed, error rate, and subjective experiences were recorded. The results showed that the model had no effect to the measured performance, but subjective experiences were affected. The Arabic numbers with slower speed were preferred most. Thus, subjectively the performance was rated as better, even though objective measures showed no differences.