Accessibility at NSW CLIC

(review date February 2007)

The DraftsMan with the ruler about a third of the way down the page. The writing on the plastic sheet, the set squares and protractor are visible.

“A picture is worth a thousand words” is not always an accurate statement where blind students are concerned. Most blind people cannot interpret complex images and this is especially true in the case of three-dimensional representations. Nevertheless, raised line diagrams are potentially very important in the education of people who are blind or have a severe vision impairment.

The process used by the DraftsMan to produce raised lines is not new, examples of varying styles having been available over more than forty years. The DraftsMan, however, represents a very good implementation of the technology.

The DraftsMan Standard accepts A4 sized plastic sheets. To keep it taut during drawing, the sheet is secured by a simple and effective bar clamp at top and bottom. Drawing with a pen (or other sharp stylus) results in the lines being raised on the plastic sheet due to its interaction with the rubbery surface of the board.

A ruler, set squares and protractor are provided. It is common for raised markings to be used on Braille rulers. The tools supplied with the DraftsMan have these, but also include niches along their edges. This is highly desirable, as it allows greater precision when locating the pen at a specific point.

On each side of the board there is a slot, which ensures that the purpose-built ruler lies directly across the page. This also allows the ruler to be moved up and down the page while maintaining a constant angle.

The ruler can be locked in a chosen position. This is especially helpful to a blind user, as it frees both hands to control the pen and to manipulate set squares. The scale on the protractor is very coarse, with marks at only every 10 degrees. While marking every degree in a tactile form would require a larger protractor, this implementation is disappointing.

Very little practice is required to establish the correct pressure when drawing on the DraftsMan. Insufficient pressure will produce faint lines, while excessive force can cut the sheet. Sharp, well defined lines are produced. While the sheets supplied with the DraftsMan are translucent, drawings made with a pen are also highly visible. While thin and light, the sheets appear to be quite resilient. When stored in folders or other options which prevent crumpling, the durability of drawings should be good.

The DraftsMan is a simple and effective tool for producing raised line diagrams both for and by students who have little or no vision. It can be used for showing anything from basic geometric shapes to flow charts and bar graphs, basic maps and other two-dimensional representations. One application is to teach the shape of print characters. Importantly, it allows blind students to draw and to receive immediate feedback on their work. It also allows people who have had no prior experience in the field of tactile graphics to produce material with very little practice.