Press release, 21 August 2002
The eyes have it
Writing fast without a keyboard
A new text entry system developed at Cambridge University could transform computing for people unable to use a normal keyboard.
The text entry system, called Dasher, designed by David MacKay and David Ward in the University's Department of Physics, can
be controlled by an eyetracker - a camera that tracks where on the screen the user is looking.
'The software works like a video game in which the user steers ever deeper into an enormous library,' explained Dr MacKay.
'A language model is used to shape this library in such a way that it's quick and easy to select probable sequences of characters and hard to make spelling mistakes.'
The system, which is described in today's Nature (22 August 2002), is much faster than any alternative writing systems driven by an eyetracker.
Experiments show that with practice, Dasher can produce up to 25 words per minute. Users writing with other eyetracker-based techniques, using on-screen keyboards, can produce only 15 words per minute.
'Not only is this faster than any alternative writing system driven by an eyetracker, the frequency of spelling mistakes is about five
times smaller - and the new system is also less stressful to use,' added Dr MacKay.
Dasher is distinctive because it is controlled by continuous pointing
gestures, so it uses humans' natural ability to make high-precision
analogue movements. A keyboard, where the hands use all-or-nothing
movements to produce text, wastes this ability.
Dasher also makes no
distinction between word completion and ordinary writing. Other
writing systems will suggest completed words in a separate part of the
display and the user has to point or stare at them to choose
them. Dasher's suggestions are integrated seamlessly into the writing
process. The language model adapts to an individual user's
writing style, so that sometimes several words can be written with a
Dasher will be particularly useful for computer users who are
unable to type using a conventional keyboard. Because it can be driven
using any pointing device - mouse, rollerball, touchpad, or eyetracker
- it is also useful for handheld computers or mobile phones where
there is no space for a keyboard. It also has potential as an
input system for other languages, such as Japanese.
David MacKay and
David Ward plan to develop Dasher as an `Open Source' software
project, like GNU/Linux.
Notes for Editors:
'Fast hands-free writing by gaze direction', by David J. Ward and David J.C. MacKay, will be published in Nature on 22 August 2002.
For more information about Dasher, including video demonstrations,
and images look at:
Further information for the press is available online.
For further information please contact:
David MacKay, Department of Physics,
University of Cambridge.
Tel: 01223 339852; e-mail: firstname.lastname@example.org
Alison McFarquhar, Press and Publications Office, University of Cambridge.
Tel: 01223 332300; e-mail: email@example.com
Cambridge University's press office.