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.
What’s important to you in the development of a product?
One of the things that really hurt Apple was that after I left John Sculley got a very serious disease. And that disease — I’ve seen other people get it too — it’s the disease of thinking that a really great idea is 90% of the work, and if you just tell all these other people “here’s this great idea,” then of course they can just go off and make it happen.
The problem with that is that there’s just a tremendous amount of craftsmanship in between a great idea and a great product. And as you evolve that great idea it changes and grows. It never comes out like it starts, because you learn a lot more as you get into the subtleties of it, and you also find there are tremendous tradeoffs you have to make, there are just certain things you can’t make electrons do, there are certain things you can’t make plastic, or glass, or factories, or robots do. And as you get into all these things, you find that designing a product is keeping 5,000 things in your brain, these concepts, and just fitting them all together and continuing to push to fit them together in new and different ways to get what you want. And every day you discover a new problem or a new opportunity to do it a little differently. And it’s that process that is the magic.