The philosophy behind user-centered design is simply this: users know best. The people who will be using a product or service know what their needs, goals, and preferences are, and it is up to the designer to find out those things and design for them. One shouldn't design a service for selling coffee without first talking to coffee drinkers. Designers, however well-meaning, aren't the users. Designers are involved simply to help users achieve their goals. Participation from users is sought (
) at every stage of the design process. Indeed, some
of user-centered design view users as co-
The concept of user-centered design has been around for a long time; its roots are in industrial design and ergonomics and in the belief that designers should try to fit products to people instead of the other way around. Industrial designer Henry Dreyfuss, who designed the iconic 500-series telephone for Bell Telephones, first popularized the method with his 1955 book
Designing for People
. But while industrial designers
this legacy, software engineers were blissfully unaware of it, and for decades they churned out software that made sense in terms of the way computers work, but not in terms of the way that people work. To be fair, this focus was not all the engineers' fault; with the limited processing speed and memory of computers for the first 40
of their existence, it's sometimes astounding that
could make computers useful at all. The constraints of the system were huge. There was little concern for the user because it took so much effort and development time simply to get the computer to work correctly.
In the 1980s, designers and computer scientists working in the new field of human-computer interaction
questioning the practice of letting engineers design the interface for computer systems. With increased memory, processing speed, and
, different types of interfaces were now possible, and a movement began to focus the design of computer software on users, not on computers. This movement became known as user-centered design (UCD).
Goals are really important in UCD; designers focus on what the user ultimately wants to accomplish. The designer then determines the
and means necessary to achieve those goals, but always with the users' needs and preferences in mind.
In the best (or at least most thorough) UCD approach, designers involve users in every stage of the project. Designers
users at the beginning of the project to see if the proposed project will even address the users' needs. Designers conduct
research (see Chapter 4) up front to determine what the users' goals are in the current situation. Then, as designers develop models
to the project (see Chapter 5), they consult users about them. Designers (often
usability professionals) test
with users as well.
Simply put, throughout the project, user data is the determining factor in making design decisions. When a question arises as to how something should be done, the users' wants and needs determine the response. For example, if during user research for an e-commerce Web site, users say they want the shopping cart in the upper-right corner of the page, when the shopping cart is ultimately positioned on the page, that's likely where the shopping cart will be.
The real targets of UCDuser goalsare notoriously
and often hard to define,
goals. Or else they are so vague that it is nearly
to design for them. Let's say a designer is creating an application to help college students manage their schedules. What's the goal there? To help students do better in school? But why? So they can graduate? What's the goal there? To get a good job? To become
? User goals can quickly become like Russian
, with goals nestled inside goals.
That being said, what UCD is best at is getting designers to move away from their own preferences and instead to focus on the needs and goals of the users, and this result should not be undervalued. Designers, like everyone else, carry around their own experiences and prejudices, and those can conflict with what users require in a product or service. A UCD approach
designers from that trap. One design dictum is "You are not the user."
UCD doesn't always work, however. Relying on users for all design insights can sometimes result in a product or service that is too narrowly focused. Designers may, for instance, be basing their work on the wrong set or type of users. For products that will be used by millions of people, UCD may be
. UCD is a
approach, but it is only one approach to design.