Let’s Get Physical
Gretchen Anderson
LUNAR | gretchen@lunar.com
Increasingly, interactions are
taking place on screens and
devices outside the desktop/PC
environment in products sometimes referred to as “convergent.”
Converging are the traditionally
distinct worlds of screen-based
interaction design and the industrial design of physical objects.
As a result, interdisciplinary
design teams must collaborate
to choose physical controls that
will delight people and lead
to a pleasing aesthetic, while
still supporting the functional
needs of the product. This often
involves balancing the desire for
simplicity of appearance with
the need for sufficient controls
to serve the product’s intended
use, with minimum effort.
Finding this balance isn’t
easy. The recent success of the
Nintendo Wii and the Apple
iPhone illustrates how much
attention has come to be focused
on the way the products are
controlled. A great deal of the
delight delivered by both products comes from the intersection of physical controls and
on-screen behavior. The “wow”
factor of both of those products
cannot be ignored, and each is
as much about being different
as they are about being useful.
This seems to suggest that the
choice of controls is not simply
an evaluation of what is usable
or learnable but also what will
delight people, and in some
cases, surprise them.
I work at a design consultancy
called LUNAR, where we engage
in a process that involves engineers, industrial designers, interaction designers, and clients, all
collaborating to bring different
perspectives and expertise to
bear. In this article I’ll describe
some of the convergent work
we’ve completed and indicate
some best practices on developing physical interactions that
offer both usability and delight.
Where Physical Meets Virtual
Convergence is a chicken-or-egg
question: Which comes first—
the controls or the behavior?
Physical controls and on-screen
interactions are inextricably
linked, and designing one in isolation from the other is a certain
path to an awkward product.
Let’s look at a few examples
of how physical controls inform
the interaction design of the
product. Consider the difference between a touch-screen
in-flight entertainment system,
an MP3 player, and the typical ATM. Virgin America’s RED
in-flight entertainment system
uses “direct manipulation,”
wherein users interact with
visible on-screen elements, yet
this seemingly novel interaction paradigm forces a new size
constraint on interface elements:
Every interactive element on the
screen must be finger-size. An
additional unintended consequence of this design decision is
that passengers press the screen
controls harder than they need
to and end up jabbing the seat
of the person in front of them.
Compare this product’s convergent interaction approach with
that of an iPod Nano. In order
to fit several songs on a single
screen, users move a cursor
and make selections using a jog
wheel. This helps keep the product small while still providing
access to a fair amount of information on the screen.
ATMs present yet another
model. “Soft keys” are used to
execute the commands that
appear on the screen next to
them. This allows for the use of
physical controls without having to either limit the number of
commands available or having a
dedicated button for every command. In many cases soft keys
are used in public interfaces, due
to concerns about the cost and
durability of the screen component. It’s worth noting that more
touch screens are appearing in
kiosk products like ATMs, as cost
and durability are improving.
These examples illustrate the
types of basic approach paradigms to consider when tackling
a convergent product.
Facilitating the Process
Product designers are often in
the position of having to define
the physical controls in advance
of designing the on-screen interactions. Choices about physical
controls affect the entirety of the
product development cycle: They
describe what parts the engineer must select, which directly
affects the final cost for the consumer. Development schedules
September + October 2008
