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.
Throughout his career, Wilson often answered fan mail and outside requests for his time with this form postcard:
Edmund Wilson regrets that it is impossible for him to: Read manuscripts, write books and articles to order, write forewords or introductions, make statements for publicity purposes, do any kind of editorial work, judge literary contests, give interviews, conduct educational courses, deliver lectures, give talks or make speeches, broadcast or appear on television, take part in writers' congresses, answer questionnaires, contribute to or take part in symposiums or 'panels' of any kind, contribute manuscripts for sales, donate copies of his books to libraries, autograph books for strangers, allow his name to be used on letterheads, supply personal information about himself, supply photographs of himself, supply opinions on literary or other subjects.