The tactile depiction of visual conventions: the advantage of explicit cues.

The introduction of representational standards for tactile diagrams might improve their use. Two elements central to the design of visual diagrams are the relative positioning and movement of the objects yet no standard convention for representing either of these in tactile form has been established. Consequently, systems representing the movement and relative positioning of objects were developed with the intention of producing design conventions for these elements. The method of depicting the element of movement was based on the concept that an object's movement is defined by changes between its initial and final positions while the method of depicting relative positioning was based on a number of the principals underlying linear perspective, along with an additional texture-based cue. Tactile diagrams making use of these systems of representation were designed and produced for exploration by eight blind participants. They were confident and accurate in their interpretations of diagrams that depicted relative positioning of objects and, on the basis of their comments on the diagrams depicting movement, a convention for the depiction of movement was proposed