Maps are a standard form of visual communication amongst geographers, geologists and environmental scientists, and play a significant role in fieldwork. Maps are not only reference sources and navigation tools, but are also a means of presenting numerical and other structured data in graphical form, through thematic mapping and spatial data visualisation. If maps are out of bounds to VI students, then their experience of field study will be considerably impoverished.
There are two broad approaches to making maps accesssible to the blind or visually impaired student:
An example of the former approach is the experience of the author who taught a near-blind student some years ago. For a map interpretation exercise, heavily simplified thick-line versions of the map handouts were prepared for the visually impaired student. Using his residual vision assisted by strong lighting he was able to make out the shapes of rivers and contours sufficiently well to enable him to comment on the spatial patterns and what they meant. We arrived at this solution by discussing with the student how we might be able to introduce him to conventional maps, which he had not previously used.
One of the benefits often claimed for digital maps is that they enable the publisher to produce maps with any combination of content and any desired symbolism. Because of the ready availability of desktop mapping and GIS software in most geography departments (e.g. MapInfo, ArcView), it is now easier than ever to convert the symbolism of a standard map into a form that is more legible by partially sighted students. Here are some useful conversions:
The most common forms of non-visual map are sonic and tactile. Although there were early experiments in producing sonic navigation aids that attempted to provide a high-information representation of the environment, many of the electronic travel aids are now restricted to providing the minimum amount of information about the environment that can support the visually impaired person's primary mobility aids. (See the accompanying document on Assistive Technology.) Some geographers have experimented with making sonic maps in which geographical data are converted to sounds so that they can be heard by visually impaired or blind students.
Tactile maps have had a longer history, and are currently widely used. (For a general description of tactile graphics, see the complementary document on assistive technology. For a general review of their educational use, see Hinton, 1994/5.) Tactile maps typically use 'raised-line' technology to enable blind or visually impaired map users to 'read' what a sighted person might see on a conventional printed map. Tactile maps consist of raised lines, shapes, textures and symbols, and are produced using a number of different technologies. The most common are:
Recent developments include the harnessing of several sensory modalities, including the tactile. One example in the TACIS system, funded by the European TIDE Programme, which uses a combination of tactile, tonescape and speech information to convey spatial information to the user.
In the UK, tactile maps can be acquired from the National Centre for Tactile Diagrams (NCTD) at the University of Hertfordshire. Maps from existing paper sources can be produced very rapidly, and entirely new tactile maps can also be produced, though these usually take longer. The costs are subsidised because of grants received from the various HE funding councils.
One of the important issues being discussed in the field of tactile map-making concerns the question of whether tactile maps should attempt to reproduce visual maps in a tactile format, or whether they should seek to represent the environment in ways that are more compatible with the visually impaired user's sense of spatial awareness. There is now considerable research being undertaken into the way in which people with visual impairments build up their awareness of the environment, and how this differs from the process adopted by fully sighted people (Challis & Edwards, 2000; Marek, 2000; Ungar, 2000).
Another issue concerns the standardisation of symbols used in tactile maps. To some extent this will be informed by research into how best to represent features that accords with users' spatial awareness. One initiative involves building a database of tactile symbols (DOTS) (Tasker, 2000).
Page updated 14 December 2001
GDN pages maintained by Phil Gravestock
© Geography Discipline Network/authors, 2001
ISBN: 1 86174 115 4