ciate professor of human-computer interaction at Queen’s University.

“One of the caveats with eye track-
ing is the notion you can point at some-
thing,” Vertegaal says. “We didn’t really
like that. People tend not to point with
their eyes. The eyes are an input device
and not an output device for the body.”
Vertegaal says this basic incom-
patibility between the eyes’ intended
function and the demands of using
them as output controllers presents
issues including the Midas Touch,
postulated by Rob Jacob in a seminal
1991 paper entitled “The Use of Eye
Movements in Human-Computer In-
teraction Techniques: What You Look
At is What You Get.”
“At first, it is empowering to be able
simply to look at what you want and
have it happen, rather than having to
look at it (as you would anyway) and
then point and click it with the mouse
or otherwise issue a command,” Ja-
cob wrote. “Before long, though, it
becomes like the Midas Touch. Every-
where you look, another command is
activated; you cannot look anywhere
without issuing a command.”
Another issue caused by trying to
make the eyes perform a task for which
they are ill-suited is the lack of a consen-
sus on how best to approach designing
an eye-controlled interface. For exam-
ple, one of the most salient principles of
mainstream UI design, Fitts’s Law, es-
sentially states that the time to move a
hand toward a target is affected by both
the distance to a target and the size of
the target. However, Fitts’s Law has not
proven to be a shibboleth among eye-
tracking researchers. Many contend
the natural accuracy limitations of the
eye in pointing to a small object, such
as a coordinate on a screen, limit its ap-
plicability. A lack of consensus on the
scientific foundation of eye control has
led to disagreement on how best to ap-
proach discrete eye control of a phone.
The Dartmouth researchers, for exam-
ple, used blinks to control the phone
in their experiment. However, Munich-
based researcher Heiko Drewes found
that designing a phone that follows gaze
gestures—learned patterns of eye move-
ment that trigger specific applications,
rather than blinks—resulted in more
accurate responses from the phone.

Steady Progress

Vertegaal believes the most profound accomplishment of the Dartmouth EyePhone work may be in the researchers’ demonstration of a mobile phone’s self-contained image and processing power in multiple realistic environments, instead of conducting experiments on a phone tethered to a desktop in a static lab setting. Dartmouth’s Campbell concurs to a large degree.

“We did something extremely
simple,” Campbell says. “We just con-
nected an existing body of work to an
extremely popular device, and kind of
answered the question of what do we
have to do to take these algorithms and
make them work in a mobile environ-
ment. We also connected the work to
an application. Therefore, it was quite a
simple demonstration of the idea.”
Specifically, Campbell’s group used
eye-tracking and eye-detection algo-
rithms originally developed for desktop
machines and USB cameras. In detect-
ing the eye, the original algorithm pro-
duced a number of false positive re-

Obituary
Benoît Mandelbrot, Mathematician, 1924–2010

Benoît Mandelbrot, working largely outside the mainstream of mathematics and computer science, achieved international fame by introducing the term “fractal” to refer to intriguing mathematical shapes that display rough and irregular patterns found in nature. the mathematician died from pancreatic cancer on october 14 at age 85.

Mandelbrot, born in poland,
raised in France, and later a
resident of Cambridge, Ma,
became interested in unusual
natural patterns—including
coastlines, plants, and blood
vessels—as a young man. He
continued to focus on geometric
complexities throughout his
career. in the 1950s, Mandelbrot
argued that it was possible to
quantify the crookedness of
complex objects by assigning a
“fractal dimension.” in 1982, he
published The Fractal Geometry
of Nature, a book that earned
him widespread acclaim.