Introduction | Web
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Designing useful and
attractive products requires skill and creativity. As products
evolve from initial ideas through conceptual design and prototypes,
iterative cycles of design and evaluation help to ensure that
they meet users' needs. But how do evaluators decide what
and when to evaluate? The HutchWorld case study in the previous
chapter described how one team did this, but the circumstances
surrounding every product's development are different. Certain
techniques work better for some than for others.
and user experience goals is essential for making every product
successful, and this requires understanding users' needs.
The role of evaluation is to make sure that this understanding
occurs during all the stages of the product's development.
The skillful and sometimes tricky part of doing this is knowing
what to focus on at different stages. Initial requirements
get the design process started, but, as you have seen, understanding
requirements tends to happen by a process of negotiation between
designers and users. As designers understand users' needs
better, their designs reflect this understanding. Similarly,
as users see and experience design ideas, they are able to
give better feedback that enables the designers to improve
their designs further. The process is cyclical, with evaluation
playing a key role in facilitating understanding between designers
Evaluation is driven
by questions about how well the design or particular aspects
of it satisfy users' needs. Some of these questions provide
highlevel goals to guide the evaluation. Others are much
more specific. For example, can users find a particular menu
item? Is a graphic useful and attractive? Is the product engaging?
Practical constraints also play a big role in shaping evaluation
plans: tight schedules, low budgets, or little access to users
constrain what evaluators can do. You read in chapter 10 how
the HutchWorld team had to plan its evaluation around hospital
routines and patients' health.
get to know what works and what doesn't, but those with little
experience can find doing their first evaluation daunting.
However, with careful advance planning, problems can be spotted
and ways of dealing with them can be found. Planning evaluation
studies involves thinking about key issues and asking questions
about the process. In this chapter we propose the DECIDE framework
to help you do this.
The main aims of this chapter are to:
- Continue to explain the key concepts
and terms used to discuss evaluation.
- Describe the evaluation paradigms
and techniques used in interaction design.
- Discuss the conceptual, practical,
and ethical issues to be considered when planning evaluation.
- Introduce the DECIDE framework to
help you plan your own evaluation