A Touch Sensitive Keypad Layout for Improved Usability of Smartphones for the Blind and Visually Impaired Persons

摘要

Blind users face a number of challenges in performing common operations of text-entry, text selection, and text manipulation on smartphones. The existing keypad layouts make it difficult for the users to easily operate a touch screen device even for entry-level activities. This necessitates the need for customizing the current keypad and dialer to enable a blind user to perform common activities of making a call, sending and receiving SMS messages and e-mails and browsing internet without visual feedback. Based on our prior study on screen division layouts, this paper proposes and evaluates a dialer and keyboard for blind users of a smartphone. The proposed keypad was tested on selected groups of blind users from both the countries where the research was performed. They were initially trained on using the proposed keypad. Their experiences were then recorded using interviews and observation. The responses were then tested and analyzed using standard statistical tests. The results were then compared with the existing ordinary and QWERTY keypads. These results show that the proposed keypad and dialer has a gentle learning curve and results in minimum typing errors thus reducing cognitive load on the blind user.