Eyes write- Typing without a keyboard just got faster and easier.

22 August 2002

New software could allow
computer users with
disabilities or busy hands
to write nearly twice as
fast, more accurately and
more comfortably than
before. The software could
also speed up writing on
palm-tops and typing in
Japanese and Chinese, its
developers say.

TOM CLARKE Nature.com

The package, called
Dasher, "exploits our
eyes’ natural ability to
navigate and spot familiar
patterns", says one of its
inventors, computer
scientist David MacKay of the Cavendish Laboratory in
Cambridge, UK.

An eye-tracking device lets users select letters from a screen.
Dasher calculates the probability of one letter coming after
another. It then presents the letters required as if contained
on infinitely expanding bookshelves.

Pick, ‘h’ for hello, for
example, and Dasher will
display the most likely
pairs – such as he, hi and
ha – most prominently on
the screen. The user
chooses the correct pair,
and Dasher suggests
triplets of letters, or
guesses what the word
might be.

"Users have the feeling
that whole syllables, whole words, even whole phrases, are
simply leaping towards them," says MacKay. He and his
colleague David Ward taught Dasher English using passages
from Jane Austen’s Emma, Lewis Carroll’s Alice in Wonderland
and other classic texts.

"It has huge potential to speed up people who at the
moment have to write quite laboriously," says John Willis, a
lawyer in Papworth, UK, who has used Dasher.

Fast text

Devices that use cameras to follow eye movement have
already been combined with on-screen keyboards. But typing
this way is slow and exhausting. The top speed is about 15
words per minute, and users have to be careful where they
look to avoid inadvertently selecting and typing things.

Dasher’s predictive abilities are "hugely advantageous", says
Willis, who was born without hands. Not only does Dasher
learn the language – providing a ‘u’ if a ‘q’ is selected, for
example – it learns each user’s favourite words.

Users can soon reach a typing speed of 25 words per minute.
"They’ve certainly broken the world record for gaze-operated
typing," says John Paulin Hansen, who works on technology
for the disabled at the IT University of Copenhagen,
Denmark.

Dasher also provides unparalleled comfort and accuracy,
Hansen adds. He foresees it entering general use: "We could
be sending [mobile phone] text messages without taking our
hands off the steering wheel."

Eye-tracking devices are
still problematic. "They
need re-calibrating each
time you look away from
the computer," says Willis.
He controls Dasher using a
trackball pointer. More
sophisticated and robust
eye trackers are under
development, says Hansen

The Cambridge team aim
to release Dasher as ‘open
source’ software in about
six months. They hope it
will find applications in
palmtop computers, which
are too small to have
proper keyboards.

Japan and China could also
be a huge market, MacKay
says. These languages,
with thousands of
characters, are poorly suited to keyboards. Dasher, which can
draw upon an unlimited pool of characters but also spot
common sequences, could be ideal. His team are testing a
prototype that uses hiragana, a Japanese character set.

References

1.Ward, D. J. & MacKay, D. J. C. Fast hands-free writing by
gaze direction. Nature, 418, 838, (2002).

© Nature News Service / Macmillan Magazines Ltd 2002

http://www.nature.com/nsu/020819/020819-5.html