This article is intended primarily for parents, teachers, and friends of blind people. It introduces the reader to some of the possibilities and to some limitations of using tactile graphics for conveying information to blind people. A number of methods for producing tactile graphics are described. A resource list of useful tools, supplies, and technological methods and devices, and the names and addresses of firms and organizations selling these products is included. A major focus of this article is tactile graphics in science, engineering, and math.
Tactile graphic images are used by blind people to obtain information that sighted people get from looking at pictures. Students learning geography for example would be lost without maps of regions being studied. A blind student without equivalent tactile maps is at an enormous disadvantage relative to sighted peers.
The unfortunate truth is that blind students seldom have tactile maps that are equivalent to visual maps. Visual maps use color and many kinds of texture to indicate such things as elevation, population density, agricultural productivity, and thousands of other variables that the authors use maps to illustrate. The information conveyed by color and texture are difficult to translate into equivalent haptic information. Even the most skilled professional does not know how to make tactile representations of many such maps that are as informative to blind readers as the visual maps are to sighted readers.
There are several problems. One is that haptic perception is much less detailed than visual perception. Another is that most blind people have little experience in reading tactile pictures. Consequently it is difficult to make tactile pictures that are very detailed without simultaneously making them confusing to blind readers. Research on haptic perception, development of inexpensive methods for making tactile graphic materials, and early training of blind children in techniques for reading tactile graphics are needed before the full potential of tactile graphic materials is likely to be realized.
This article provides an overview of the state-of-the art in preparation and use of tactile graphics as well as a brief description of research on these topics that is underway in the author's research group. Reference is made to a few other research efforts as well.