Metrics add structure to the design and evaluation process, give insight into the findings, and provide information to the decision makers.
By Tom Tullis   |   Second Edition 2022   |   UX Metrics, Data Driven Design

What are user experience metrics?

A metric is a way of measuring or evaluating a particular phenomenon or thing. We can say something is longer, taller, or faster because we are able to measure or quantify some attribute of it, such as distance, height, or speed. The process requires agreement on how to measure these things, as well as a consistent and reliable way of doing it. An inch is the same length regardless of who is measuring it, and a second lasts for the same amount of time no matter what the time-keeping device is. Standards for such measures are defined by a society as a whole and are based on standard definitions of each measure.

The value of UX Metrics

We think UX metrics are pretty amazing. Measuring the user experience offers so much more than just simple observation. Metrics add structure to the design and evaluation process, give insight into the findings, and provide information to the decision makers. Without the insight provided by metrics, important business decisions may be made based on incorrect assumptions, “gut feelings,” or hunches. As a result, some of these decisions are not the best ones. During a typical usability evaluation, it’s fairly easy to spot some of the more obvious usability issues. But it’s much harder to estimate the size or magnitude of the issues. For example, if all eight participants in a study have the same exact problem, you can be quite certain it is a common problem. But what if only two or three of the eight participants encounter the problem? What does that mean for the larger population of users? UX metrics offer a way to estimate the number of users likely to experience this problem. Knowing the magnitude of the problem could mean the difference between delaying a major product launch and simply adding an additional item to the bug list with a low priority. Without UX metrics, the magnitude of the problem is just a guess.

Ten MYTH about UX Metrics:

  • Myth 1: Metrics Take Too Much Time to Collect
  • Myth 2: UX Metrics Cost Too Much Money
  • Myth 3: UX Metrics are not Useful When Focusing on Small Improvements
  • Myth 4: UX Metrics Don’t Help us Understand Causes
  • Myth 5: UX Metrics are Too Noisy
  • Myth 6: You Can Just Trust Your Gut
  • Myth 7: Metrics Don’t Apply to New Products
  • Myth 8: No Metrics Exist for the Type of Issues We are Dealing with
  • Myth 9: Metrics are not Understood or Appreciated by Management
  • Myth 10: It’s Difficult to Collect Reliable Data with a Small Sample Size