BrailleTap: a mobile device text-entry method focused on the users

Regular mobile device text-entry methods are suitable for visually capable individuals and seek to improve user’s performance. Hence, it is possible for someone, with no experience, who doesn’t remember the location of a letter, to easily look and recognize the key where that letter is. Those methods imply that the fingers dance through the keyboard, choosing letters and special characters, among ten or more keys. Once again, we easily overcome this issue appealing to vision. A blind user is not able to do so. The mark present at key ‘5’ gives blind users the notion of the keypad layout but not feedback on the selected letter and, although users can make an effort to memorize a letter’s placement, feedback is essential. Even SMS experts need to occasionally look at the words being written to ensure message correction. Moreover, expertise is acquired by using the method and receiving the feedback. Only after an extensive and successful use of the writing mechanisms the users can get used to them and, in some cases, no longer need constant visual feedback. Screen readers overcome some of the issues as they offer the user feedback on the screen progress. However, keypad feedback is still inexistent which often leads to mistakes and sometimes giving up. Although users make sense on the message progress, they still have to know where to press to get the desired letter/action.

We can only offer visually impaired individuals mobile device accessibility if those devices can be easily available and usable. Therefore, based on user needs, capabilities and available devices we decided that, like in the NavTap method, our solutions should be compatible with regular mobile phones and, therefore, with the regular 12 key keyboard layout requiring no-extra hardware (i.e. expensive and heavy Braille keyboards). Having this in mind, we looked at the regular mobile phone keypad to find out a way of permitting Braille input without the needs of additional hardware.

BrailleTap focuses on a common knowledge to many blind users: the Braille Alphabet. Again, transforming the keypad functionalities is the basis of this new text-entry method. In the Braille alphabet, letters are formed by groups of 6 dots in a 3x2 cell.



Considering the keypad of a mobile phone we can map that cell on keys ‘2’, ‘3’, ‘5’, ‘6’, ‘8’ and ‘9’. Each press on these keys fills or blanks the respective dot. Key ‘4’ allows the user to enter the letter or, if all dots are blank, enter a space. For example, to enter the letter ‘b’, the user has to press keys ‘2’ and ‘5’ followed by key ‘4’. Finally, key ‘7’ erases the last character entered.



Although capitalized letters are not considered in these studies it would be possible to augment the functionality as some keys still remain available.
This method focuses on the user and replaces the non-memorisable keypad layout with a particular common knowledge within this user group.

Take a look at this video for a demonstration:

If you are interested in more detail, particularly about the user studies, you can take a look at our publications on BrailleTap:

Tiago Guerreiro, Paulo Lagoá, Pedro Santana, Daniel Gonçalves, Joaquim Jorge, Navtap and Brailletap: Non-visual input interfaces, RESNA 2008 - Rehabilitation Engineering and Assistive Technology Society of North America Conference, Arlington, USA, June 2008

Pedro Santana, Tiago Guerreiro, Joaquim Jorge, Braille Matrix, Proceedings of the International Conference on Software Development for Enhancing Accessibility and Fighting Info-exclusion, Vila Real, Portugal, November 2007

Check the presentation I have made in Vila Real, at DSAI 2007, on this new text-entry method:

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Credits:
Paulo Lagoá (Developer)
Pedro Santana (Developer)
Tiago Guerreiro (Developer Team Leader)
Joaquim Jorge (Adviser)