display. What kind of new interfaces would be possible with such a hypothetical device?
The resulting interface concept and prototype
allows users to browse digital media by a combination of physical deformation and 2D position control. Held in both hands, the device can be bent
along one axis while a touchpad mounted on the
back of the device is used to control 2D position.
With a simple, consistent vocabulary of physical
interactions, it is possible to navigate file structures,
maps, hyperlinks, photo albums, and movies. We
also implemented a street map that can be scrolled
Figure 2. Gummi device and interaction.
with the touchpad and zoomed by bending the
device (see Figure 1). The flat prototype can be
bent either away from or toward the user to control
zoom direction (see Figure 2). The amount of
bending is mapped to zoom speed: slight deformation results in a slow, continuous zoom; stronger
bending increases the zoom speed. This kind of
analog interaction has two benefits. It gives the
user finer control over the feature in question and
it feels organic because it is as sensitive to the
nuances and transitions of physical interaction as a
Although Gummi was inspired by new hardware
technology, the use of analog sensors in the resulting prototype became a focus for the project. We
realized that capturing analog, continuous physical
interaction led to an interface that offered interest-
ing new functional possibilities, while at the same
time feeling very organic.
Two recently released products feature analog
interaction techniques. The Nintendo Wii gaming
platform includes an input device that adds hand
and arm gestures to the interaction vocabulary of
game interfaces. Apple’s iPhone represents the first
mass-marketed product that uses multi-touch interaction. Its responsive graphical user interface incorporates subtle, animated visual behaviors that add
up to create a very tactile, organic user experience.
Analog interaction techniques arguably played
an important role in the success of both the Wii and
the iPhone and recent technological developments
suggest there is a lot of room for exploration in this
area: small, inexpensive sensors can capture a wide
range of analog physical inputs such as gestures,
pressure, deformation, multi-point touch, orientation, and location. New materials, such as organic
LED displays, point toward flexible computers that
can sense their own shape. Mobile devices with fast
processors and high-resolution displays support
graphical user interfaces that can match the subtle,
analog nature of physical interaction.
The examples mentioned here share a number of
characteristics that contribute to the organic feel of
these interfaces: by using analog sensors in input
devices, continuous and subtle changes in physical
interaction can be measured. The analog complexity of input is reflected in a highly responsive graphical user interface, featuring smooth animation and
consistent visual behavior. As a result, the input
device and graphical user interface are experienced
as a whole, not as independent elements of the
interface. The cumulative effect of these characteristics is a user interface that inspires a suspension of
disbelief: intangible information feels as though it is
part of our tangible physical environment. c
1. Schwesig, C., Poupyrev, I., and Mori, E. Gummi: A bendable computer. E. Dykstra-Erickson and M. Tscheligi, Eds. In Proceedings of
ACM CHI 2004 Conference on Human Factors in Computing Systems
(Vienna, Austria, 2004), 263–270.
CARSTEN SCHWESIG ( firstname.lastname@example.org) is an interaction
designer and researcher at Sony in Tokyo, Japan.
© 2008 ACM 0001-0782/08/0600 $5.00