Designed for Use, 2nd Edition

What’s Success?

The basic idea behind A/B testing is to implement two different designs and see which one works better. But there’s an inherent problem with this. What exactly does “works better” mean? At what point has the user successfully used your product? Sometimes, the answer is obvious. For example, in designing a checkout system, the system “works” when the user is able to finish the checkout process. Often, however, there is no immediately obvious answer to what constitutes “success.”

One way to define “success” is to go back to the very beginning of the design process and think about your users’ goals. If you know why they use the product, then you can define success: the product works better if a higher percentage of your users are ...