Tactual Maps: Discriminability of Textures and Shapes

Abstract

Report of a study of the discriminability of point symbols in tactual maps which showed that the three shapes and four textures tested are distinguishable in sizes 7.9 mm (.3 in.) and larger. Suggestions for the use of textures in tactual maps are offered.

An Evaluation of Substrates for Tactile Maps and Diagrams: Scanning Speed and Users’ Preferences

“…Figure 1 presents an example of the displays. Symbols were 8 by 8 millimeters (.315 inch by .315 inch), except for the ellipse, which was 5.5 by 11 millimeters (.216 by .433 inch), which is a size at which symbols have been shown to be readily identifiable and discriminable (Horsfall & Vanston, 1981). The width of the line was 1.3 millimeters (.05 inch), and the height was nominally 340 micrometers (.0134 inch).…”