The researchers from the Cavendish Laboratory at the University of Cambridge developed a usable system called Dasher that allows the the insertion of text in situations wherever a full-size keyboard cannot be used . For example, Dasher can be used:
- when operating a computer one-handed, by joystick, touchscreen, trackball, or mouse;
- when operating a computer with zero hands (i.e., by head-mouse or by eyetracker);
- on a palmtop computer;
- on a wearable computer.
Dasher is a zooming interface and it contains a vertical line of letters from A to Z. To start typing, you simply point towards the letter you want to start your sentence with and the display zooms in wherever you point. The more you zoom in, the longer the piece of text you have written.
Dasher runs on Microsoft Windows and UNIX systems, it has text predicting functionality and is available in many languages. In addition, just by typing away you can easily train Dasher on using your preferred writing style. So, keep tightly onto your seat and test the usefulness of Dasher in your browser here.
An expert user of Dasher with a mouse as the input device has a writing speed of about 34 words per minute, whereas a novice user writes over 20 words per minute. Furthermore, users of Dasher make fewer errors than people using a conventional keyboard.
Dasher is highly appropriate for computer users with lower ranges of physical capability. It can be driven using a mouse, a trackpad, a touchscreen, a rollerball, or a joystick – any two-dimensional pointing device that can take over the role of a mouse. A foot mouse and a head mouse are additional options. Apparently, the functionality of Dasher has been discussed with Stephen Hawking’s assistant, however, it is yet not known how Stephen Hawking rates the usability and usefulness of this system.