How blind individuals discriminate braille characters: An identification and comparison of three discrimination strategies

This study investigated (1) how blind individuals describe discriminating braille characters, including ranking braille features in importance – their discrimination strategy: explored qualitatively, and (2) whether exploration time, accuracy, and after-decision certainty in detecting one target among distractors depend on discrimination strategy: tested quantitatively. In all, 23 blind individuals participated. Three discrimination strategies and their phases of attention when processing information were identified: the figure identity strategy with two phases of focused attention, the global characteristics strategy with one pre-attentive phase, and the touch vision strategy with one phase of semi-focused and one of narrowly focused attention. The figure identity strategy and the global characteristics strategy were equally fast, accurate, and used with equal amounts of after-decision certainty. Exploration time, accuracy, and after-decision certainty of the touch vision strategy varied according to visual experience. In teaching, the pupil’s nonobligatory pattern of decisions needs to be recognised, whether occasional or signalling a discrimination strategy.