DUCK: A DeDUCtive Soft Keyboard for Visually Impaired Users.

Touch screens rapidly and significantly replace physical keyboards on mobile devices. Hence, text entry is now dependent on soft keyboards that are widely used by sighted people, but raise accessibility issues for visually impaired users. These users rely on tactile exploration with vocal feedback of the whole screen for entering text, which is time consuming. A software keyboard that aims reducing tactile exploration and speeding up text entry for VI users was designed. It relies on the selection of the first letter of a word and rapid and inaccurate typing of the remaining letters. It then proposes a list of words having the same first letter and a similar total distance between letters. The evaluation with twelve VI users showed that this keyboard is very efficient for words larger than five characters. It also helps preventing certain typing errors.