Introduction | Web
Resources | Assignment
Comments | Teaching Materials
Textbooks about design and usability testing
often make the processes sound straightforward and able to
be followed in a stepbystep manner. However, in
the real world bringing together all the different aspects
of a design is far from straightforward. It is only when you
become involved in an actual design project that the challenges
and multitude of difficult decisions to be made become apparent.
Iterative design often involves carrying out different parts
of a project in parallel and under tremendous pressure. The
need to deal with different sets of demands and tradeoffs
(e.g., the need for rigorous testing versus the very limited
availability of time and resources) is a major influence on
the way a design project is carried out.
The aim of this final chapter is to convey
what interaction design is like in the real world by describing
how others have dealt with the challenges of an actual de
sign project. As you will have noticed, we have written primarily
about design in Chapters 6-9 and evaluation in Chapters 10-14.
This was to enable us to explain the different techniques
and processes involved during a design project. It is important
to realize that in the real world these two central aspects
are closely integrated. You do not do one without the other.
In particular, the main reason for doing an evaluation is
to make progress on a design.Conversely, whenever you develop
a design you need to evaluate it. Whether you are designing
a small handheld device or a large airtraffic control
system, a design that takes months to produce or one that
spans years of effort, the two processes must be carried out
The chapter provides glimpses into the design
and evaluation process for quite different types of interactive
systems. The first two case studies discuss the design of
mobile communicators for different groups of users, showing
how the design is sues differ for each group. The third
case study examines the redesign of a large interactive voice
response system. In the original design, the focus was on
developing a system where the programmers used themselves
as models of the users. Further more, the programmers
were more concerned with developing elegant programs than
with users' needs for easy interaction. As you will see, this
caused a mismatch between their design and how users tried
to find information. This is a common predicament and interaction
designers are often brought in to fix already badly designed
The main aims of this
chapter are to:
- Show how design and evaluation are brought
together in the development of interactive products.
- Show how different combinations of design
and evaluation methods are used in practice.
- Describe the various design tradeoffs
and decisions made in the real world.