| Web Resources | Assignment
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Recently I met two web
designers who, proud of their newest site, looked at me in
astonishment when I asked if they had tested it with users.
"No,'' they said "but we know it's OK.'' So, I probed
further and discovered that they had asked the "web whizkids''
in their company to look at it. These guys, I was told, knew
all the tricks of web design.
The web's presence has
heightened awareness about usability, but unfortunately this
reaction is all too common. Designers assume that if they
and their colleagues can use the software and find it attractive,
others will too. Furthermore, they prefer to avoid doing evaluation
because it adds development time and costs money. So why is
evaluation important? Because without evaluation, designers
cannot be sure that their software is usable and is what users
want. But what do we mean by evaluation? There are many definitions
and many different evaluation techniques, some of which involve
users directly, while others call indirectly on an understanding
of users' needs and psychology. In this book we define evaluation
as the process of systematically collecting data that informs
us about what it is like for a particular user or group of
users to use a product for a particular task in a certain
type of environment.
As you read in Chapter
9, the basic premise of usercentered design is that users'
needs are taken into account throughout design and development.
This is achieved by evaluating the design at various stages
as it develops and by amending it to suit users' needs (Gould
and Lewis, 1985). The design, therefore, progresses in iterative
cycles of designevaluate-redesign. Being an effective
interaction designer requires knowing how to evaluate different
kinds of systems at different stages of development. Furthermore,
developing systems in this way usually turns out to be less
expensive than fixing problems that are discovered after the
systems have been shipped to customers (Karat, 1993). Studies
also suggest that the business case for using systems with
good usability is compelling (Dumas and Redish, 1999; Mayhew,
1999): thousands of dollars can be saved.
Many techniques are available for supporting
design and evaluation. Chapter 9 discussed techniques for
involving users in design and part of this involvement comes
through evaluation. In this and the next four chapters you
will learn how different techniques are used at different
stages of design to examine different aspects of the design.
You will also meet some of the same techniques that are used
for gathering user requirements, but this time used to collect
data to evaluate the design. Another aim is to show you how
to do evaluation.
This chapter begins by discussing what evaluation
is, why evaluation is important, and when to use different
evaluation techniques and approaches. Then a case study is
presented about the evaluation techniques used by Microsoft
researchers and the Fred Hutchinson Cancer Research Center
in developing HutchWorld (Cheng et al., 2000), a virtual world
to support cancer patients, their families, and friends. This
case study is chosen because it illustrates how a range of
techniques is used during the development of a new product.
It introduces some of the practical problems that evaluators
encounter and shows how iterative product development is informed
by a series of evaluation studies. The HutchWorld study also
lays the foundation for the evaluation framework that is discussed
in Chapter 11.
The main aims of this
chapter are to:
- Explain the key concepts and terms
used to discuss evaluation.
- Discuss and critique the HutchWorld
- Examine how different techniques
are used at different stages in the development of HutchWorld.
- Show how developers cope with realworld
constraints in the development