Degree of accuracy in perceiving graphic and representational information through touch

Two studies are reported in which comprehension and interpretation of raised-line images and graphs by touch were investigated. Experiment 1 required blind-folded sighted subjects and blind subjects to rate the veracity of raised-line drawings in conveying the nature of an image when the complexity of the depicted object was manipulated (from simple outlines to more complex exaggeration of salient features). Results showed no effect of complexity on veracity ratings. Experiment 2 involved the assessment of blind and visually impaired subjects of line-graphs, histograms and pie charts which varied in information content and perceptible detail (textured and untextured). Histograms were easier to interpret than line-graphs, but there were no differences between histograms and pie charts. An increase in information content had little effect on comprehension.