Touch-screen phones tend to require constant visual attention, thus not allowing eyes-free interaction. For users with visual impairment, or when occupied with another task that requires a user’s visual attention, these phones can be difficult to use. Recently, marks initiating from the bezel, the physical touch-insensitive frame surrounding a touch screen display, have been proposed as a method for eyes-free interaction. Due to the physical form factor of the mobile device, it is possible to access different parts of the bezel eyes-free. In this paper, we first studied the performance of different bezel menu layouts. Based on the results, we de- signed a bezel-based text entry application to gain insights into how bezel menus perform in a real-world application. From a longitudinal study, we found that the participants achieved 9.2 words per minute in situations requiring minimal visual attention to the screen. After only one hour of practice, the participants transitioned from novice to expert users. This shows that bezel menus can be adopted for realistic applications.
Bezel menus enable interaction with a touch-screen phone with minimal visual attention, along with solving the occlusion and mode-switching problem. They ameliorate the fat- finger problem. Marks do not have to be very precise. Bezel menus can work under direct sunlight, when it is difficult to access the on-screen controls. They can make the display icon-free, resulting in more screen space for the actual con- tent. Complex realistic applications such as video editor, word processor, text entry, which requires numerous controls along with large content viewing area can take ad- vantage of bezel menus. One of the demerits is that the number of menu items is limited to 64, and only 32 for best performance, but we believe that 32 menu items is a reasonable upper limit for most mobile applications. Also users would need to learn different command sets for different applications, but with regular practice, accessing frequently-used items eyes-free would be achievable.
The study shows that highly accurate eyes-free interaction is achievable with L8x4 layout. To gain insight into the performance of a bezel-based system we developed a bezel- based text entry technique. We found it to be competitive with existing techniques in terms of speed, accuracy, and ease of learning and usage. This shows that bezel-initiated marks can be used to interact with realistic touchscreen applications, while paying minimal visual attention to the screen. While encouraging, these results must be interpret- ed with caution. The small sample size, non-native speakers as participants, limited our analyses. More participants are required to make a stronger claim.
As the accuracy of originating the mark from the correct bezel is very high, different variations of bezel menu such as (a) both level-1 and level-2 marks starting from the bezel similar to simple marking menus , and (b) marks starting and ending at the bezels, are worth exploring. Bezel menu can provide a 2-layer interaction on a touch-screen phone, as the first layer can be on-screen controls, and the second layer of menus can be pulled out from the bezel. The obtained results are not limited to text entry, and can be readily applied to other applications. We hope that our work will inform future designers to design better bezel- based interaction techniques.
This study, although based upon the use of on iOS device, actually describes the workings of a Blackberry Playbook which has these bezel features built it. Swiping off-screen to gain on screen menus and actions does have its merits, and this research fails to point out the sense of reward a user can gain by simply swatting an application back to the menu or swiping to gain new controls. Bezel menus are an interesting concept for GUI design and although not directly relevant to my research area it is one that has some implications on the design phase of a new interface or feature.