Testing

Once you have a prototype, a logical audience for it is its intended usersthe product or service should be tested with users. This process is usually called user testing, but that's really a misnomer; it's the product or service that's being tested, not the users (Figure 5.17).

Figure 5.17. A digital prototype is tested by a user at home.

The same rules that guide design research (see Chapter 4) also guide testing: you go to the users, you talk to them, you write things down. Unless what is being tested is a service that requires a prototyped space or some other significant setup, testing is best done in the subject's own environment: on the subject's computer, in the subject's home or office, in the subject's city or town. Testing labs have only one advantage: efficiency. The designer can quickly see many subjects in a single day, one after the other, without having to change location, and there is only one setup.

Testing is also the time when any wrong conclusions reached during design research can be corrected. Designers may find that they drew the wrong implications from the research. By talking to users during testing, those misconceptions can be cleared up. Ideally, designers will carry a set of wireframes and other documents during testing and make notes right there about any patterns they see. For example, if users keep stumbling while attempting to complete a registration form, the designer should plan to revise that form later.

Designers, when testing, should not be defensive about their designs; indeed, it is often best if designers allow other team members or usability specialists to conduct the testing while they simply observe and take notesfor the designer to be present, but not guiding. The human tendency is to nudge subjects ("Why don't you just look over there at that button?") because the designer knows the design better than the subject. To avoid inhibiting testers, designers should avoid identifying themselves as the product's designer. Knowing that the designer is present may cause testers to change or soften their feedback.

Most experienced designers know one truism: you seldom get it right the first time. Testing will reveal the flaws, both known and unknown. Nothing is more humbling for designers than watching users stumble through their designs. While testing, good designers watch for the same thing they watched for in design research: patterns. Then they go back to the wireframes and prototypes and fix the errors. Then they test them again. This is how products and services should be made.