O'Reilly logo
  • Aaron Wolfson thinks this is interesting:

With Lean UX, you must learn how to design the right kinds of tests in order to know when your hypotheses have been validated. And sometimes you just have to rely on plain old qualitative research and good judgment.

From

Cover of UX for Lean Startups

Note

Exactly like experimental psychology. The experiment must be designed in order to make it clear whether the desired result is achieved or not.