I think the biggest mistake is failing to use quantitative customer interviews. Why use quantitative questions for interviews, not just qualitative? Two reasons. First, qualitative interviews give you reams of customer quotes with no good way to prioritize customer needs. Sure, you could count the number of times customers cite a need, but frequency of remarks is a poor substitute for customer eagerness to improve.
More important, with only qualitative interviews you’ll succumb to confirmation bias… the tendency to hear and interpret information according to your preconceived notions. With quantitative questions for interviews, you’ll have hard data on customer needs that your team hasn’t filtered or skewed. You get 100% unadulterated insight straight from the customer.
More in 2-minute video, Quantitative interviews are a must