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2 Chapter 1 What is interaction design?

bringing usability into the design process. In essence, it is about developing interactive
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products that are easy, effective, and enjoyable to use-from the users' perspective.
In this chapter we begin by examining what interaction design is. We look at
the difference between good and poor design, highlighting how products can differ
radically in their usability. We then describe what and who is involved in interac-
tion design. In the last part of the chapter we outline core aspects of usability and
how these are used to assess interactive products. An assignment is presented at
the end of the chapter in which you have the opportunity to put into practice what
you have read, by evaluating an interactive product using various usability criteria.
The main aims of the chapter are to:
Explain the difference between good and poor interaction design.
Describe what interaction design is and how it relates to human-computer
interaction and other fields.
Explain what usability is.
Describe what is involved in the process of interaction design.
Outline the different forms of guidance used in interaction design.
Enable you to evaluate an interactive product and explain what is good and
bad about it in terms of the goals and principles of interaction design.

1.2 Good and poor design

A central concern of interaction design is to develop interactive products that are
usable. By this is generally meant easy to learn, effective to use, and provide an en-
joyable user experience. A good place to start thinking about how to design usable
interactive products is to compare examples of well and poorly designed ones.
Through identifying the specific weaknesses and strengths of different interactive
systems, we can begin to understand what it means for something to be usable or
not. Here, we begin with an example of a poorly designed system-voice mail-
that is used in many organizations (businesses, hotels, and universities). We then
compare this with an answering machine that exemplifies good design.
Imagine the following scenario. You're staying at a hotel for a week while on a
business trip. You discover you have left your cell (mobile) phone at home so you
have to rely on the hotel's facilities. The hotel has a voice-mail system for each
room. To find out if you have a message, you pick up the handset and listen to the
tone. If it goes "beep beep beep" there is a message. To find out how to access the
message you have to read a set of instructions next to the phone.
You read and follow the first step:
"1. Touch 491".
The system responds, "You have reached the Sunny Hotel voice message center.
Please enter the room number for which you would like to leave a message."

'We use the term interactive products generically to refer to all classes of interactive systems,
technologies, environments, tools, applications, and devices.