Dasher (software)

Dasher is a graphical prognostic text entry system, which allows users efficient text input by a pointing device with continuous characters gestures instead of a keyboard. Thus, it can serve as barrier- free control of computers or be used when the use of a usable keyboard, for example, the size or the intended use (eg, for one-hand operation or without hand use ) of the device difficult or not possible. The program is suitable for all written languages ​​.

It draws on an arcade game as you drive in use by flying across the screen characters. It uses a probability- based forecast model to provide probable characters ( combinations ) in the foreground. The principle can be described as a reversed version of the arithmetic coding, a data compression technique. Besides being used Fitts' law, which states that larger areas can be selected faster than smaller ones.

Further working on a version, which combines the Dasher principle with voice recognition so as to improve the efficiency of text entry once again. For this purpose, a word lattice is generated, whose probabilities on possible ambiguities / errors based on the part of the speech recognition software.

Dasher is available as free software under the GPL, among others for Linux, Windows and Android and Apple iOS are available. An older version is also available for Pocket PC devices.

Dasher was invented by David JC MacKay and developed by David Ward and other members of MacKay's research group at the University of Cambridge. The Dasher project is supported by the Gatsby Charitable Foundation.