Observables are better, but self reported metrics do still have value. It's an aggregate version of the problem devs encounter when doing usability testing. Use

Observables are better, but self reported metrics do still have value. It's an aggregate version of the problem devs encounter when doing usability testing. Users will tell you what their experience is, but it's up to you as a software designer to distill that feedback into actual needs. Which may not at all be what they actually ask for. Survey responses are similar in that they don't tell you exactly what to do, but they do contain actionable information if you have the skill to interpret it.