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.
"Artists need to be in there from the start, making the argument for quality. The key to this thing is, for example, if you give an engineer a set of criteria which does not include a quality quotient, as it were—that is, if this sense of the quality, the character of the place, is not a part of his original motivation—he will then basically put the road straight down the middle. He has no reason to curve it. But if I can convince him that quality is absolutely a worthwhile thing and we can work out a way in which the road can be efficient and also wander down by the river, then we essentially have both: he provides his sort of expertise in that the road works, I provide quality in that it passes by the river. In that way, art gets built into the criteria from the beginning rather than being added on afterward."