Quantitative testing tells us what's happening (or not), but it can't tell us why, and what to do to correct the situation. That's why we do qualitative testing. If users and customers are not responding to a product the way we had hoped, we need to figure out why that's the case.
As a reminder, qualitative testing is not about proving anything. That's what quantitative testing is for. Qualitative testing is about rapid learning and big insights.
When you do this type of qualitative user testing, you don't get your answer from any one user, but every user you test with is like another piece of the puzzle. Eventually, you see enough of the puzzle that you can understand where you've gone wrong.
I know this is a big claim, but I argue that qualitative testing of your product ideas with real users and customers is probably the single most important discovery activity for you and your product team. It is so important and helpful that I push product teams to do at least two or three qualitative value tests every single week. Here's how to do it:
We generally begin the user test with a short user interview where we try to make sure our user has the problems we think she has, how she solves these problems today, and what it would take for her to ...