Page 121 -

90 Chapter 3 Understanding users

3.3 Applying knowledge from the physical world
to the digital world

As well as understanding the various cognitive processes that users engage in when
interacting with systems, it is also useful to understand the way people cope with
the demands of everyday life. A well known approach to applying knowledge
about everyday psychology to interaction design is to emulate, in the digital world,
the strategies and methods people commonly use in the physical world. An as-
sumption is that if these work well in the physical world, why shouldn't they also
work well in the digital world? In certain situations, this approach seems like a
good idea. Examples of applications that have been built following this approach
include electronic post-it notes in the form of "stickies," electronic "to-do" lists,
and email reminders of meetings and other events about to take place. The stickies
application displays different colored notes on the desktop in which text can be in-
serted, deleted, annotated, and shufffed around, enabling people to use them to re-
mind themselves of what they need to do-analogous to the kinds of externalizing
they do when using paper stickies. Moreover, a benefit is that electronic stickies are
more durable than paper ones-they don't get lost or fall off the objects they are
stuck to, but stay on the desktop until explicitly deleted.
In other situations, however, the simple emulation approach can turn out to be
counter-productive, forcing users to do things in bizarre, inefficient, or inappropri-
ate ways. This can happen when the activity being emulated is more complex than
is assumed, resulting in much of it being oversimplified and not supported effec-
tively. Designers may notice something salient that people do in the physical world
and then fall into the trap of trying to copy it in the electronic world without think-
ing through how and whether it will work in the new context (remember the poor
design of the virtual calculator based on the physical calculator described in the
previous chapter).
Consider the following classic study of real-world behavior. Ask yourself, first,
whether it is useful to emulate at the interface, and second, how it could be ex-
tended as an interactive application.
Tom Malone (1983) carried out a study of the "natural history" of physical of-
fices. He interviewed people and studied their offices, paying particular attention to
their filing methods and how they organized their papers. One of his findings was
that whether people have messy offices or tidy offices may be more significant than
people realize. Messy offices were seen as being chaotic with piles of papers every-
where and little organization. Tidy offices, on the other hand, were seen as being
well organized with good use of a filing system. In analyzing these two types of of-
fices, Malone suggested what they reveal in terms of the underlying cognitive be-
haviors of the occupants. One of his observations was that messy offices may
appear chaotic but in reality often reflect a coping strategy by the person: docu-
ments are left lying around in obvious places to act as reminders that something has
to be done with them. This observation suggests that using piles is a fundamental
strategy, regardless of whether you are a chaotic or orderly person.
Such observations about people's coping strategies in the physical world bring
to mind an immediate design implication about how to support electronic file