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.
I’m finding that many people not only have lowered their standards with regard to the user interface, but more and more often when I bring up the subject, they seem to consider it a somewhat secondary aspect, something that’s only good for ‘geek talk’. The same kind of amused reaction laymen have to wine or coffee connoisseurs when they describe flavours and characteristics using specific lingo. Something that makes sense only to wine or coffee geeks but has little to no meaning or impact for the regular person.
The problem is that if an increasing number of people start viewing user interface design as an afterthought, or something that isn’t fundamental to the design of a product or experience — it’s all just ‘geek talk’ — then there is a reduced incentive to care about it on the part of the maker of the product.