Once you see that an answer is not serving its question properly anymore, it should be tossed away. It's just their natural life cycle.
They usually kick and scream, raising one hell of a ruckus when we ask them to leave. Especially when they have been with us for a long time.
You see, too many actions have been based on those answers. Too much work and energy invested on them. They feel so important, so full of themselves. They will answer to no one. Not even to their initial question!
The hardest thing about customer interviews is knowing where to dig. An effective interview is more like a friendly interrogation. We don’t want to learn what customers think about the product, or what they like or dislike — we want to know what happened and how they chose... To get those answers we can’t just ask surface questions, we have to keep digging back behind the answers to find out what really happened.
Repair is a neglected, poorly understood, but all-important aspect of technical craftsmanship. The sociologist Douglas Harper believes that making and repairing form a single whole; he writes of those who do both that they possess the "knowledge that allows them to see beyond the elements of a technique to its overall purpose and coherence. This knowledge is the 'live intelligence, fallibly attuned to the actual circumstances' of life. It is the knowledge in which making and fixing are parts of a continuum."
Put simply, it is by fixing things that we often get to understand how they work.