Using Mobile Keypads With Limited Visual Feedback: Implications To Handheld And Wearable Devices

Mobile devices are often used in busy contexts, where the operation takes place - at least temporarily - with limited visual information. In such 'blind use', the passive tactile properties of the device become crucial. Two mobile keypads with very different tactile properties were tested in an experiment with twelve experienced mobile phone users. Results highlight the importance of passive tactile feel. Most clear differences were seen in errors: while the keypad with high tactile cues could be used even in total absence of visual information, the performance with low tactility keypad collapsed. This underlines the importance of the industrial design in creating mobile devices that are accessible by anyone, in any context. Wearable keypads may also benefit from indirect visual feedback shown on the display. In this study, simple indirect feedback increased subjective ease, although only moderate effects were found in performance. Also more sophisticated feedback types need to be studied.