An accessible keyboard for your desktop

Child's Play

The user chooses characters with a pointer device that moves across various colored surfaces, each representing various types of characters, such as small and capital letters or punctuation marks over crosshairs located in the middle of the screen. At this point a selection has been made. Entering text with Dasher causes the system to learn so that it can make recommendations when characters or words are entered. It is also possible to copy the text written to the clipboard for transfer to other applications.

A good overview of how the input method works is available on YouTube [13]. An extract from a Google TechTalk shows a lecture given by MacKay in which he demonstrates the efficient use of Dasher [14]. In this video, MacKay explained the origin, principles, and use of Dasher. If you have a serious interest in learning about the software, you will find the full-length lecture extremely helpful [15]. The best documentation for Dasher has been prepared by the Gnome project [16].

Conclusion

During tests, Dasher worked best under Fedora with Gnome. Unfortunately, under Debian, the program reveals some persistent bugs and gaps in functionality. The first half hour of using the software is strenuous, with a fairly high error rate. Once past this initial hurdle, ambition takes over and you discover a fascinating new world of writing. The operation offers special advantages to persons unable to control a mouse by hand (Figure 6), and it promises speeds not attainable with an onscreen keyboard.

Figure 6: Dasher with an eye scanner.

One quote from the forum gives expression to this promise: "According to the (Dasher) developers, it should be possible to write up to 125 characters per minute. This seems exaggerated to me. I myself can only achieve 80 to 90 characters per minute with the mouse. However, this is a significant improvement over an onscreen keyboard with which I can only enter 40 characters per minute, even with use of word prediction. This means I now need only half the time for everything I write. Since I write a lot, this has been a great advantage for me" [17].