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 concerned with how I witness the work of user experience practitioners getting treated: like it’s just a set of motions toward a product’s all-important implementation, and one that we try to compress, due to its ostensible superfluity. Once the implementation is finished, the UX work appears to usually get discarded.
I submit that the materials that form the precursors to a product’s implementation have considerable value on their own.
My vision is that I will be able to ask a question as mundane as one about the wording of a single button, and trace the answer all the way back to the overarching business strategy to see that it makes sense.
It isn’t a site, or a service, or even an identifiable product at all, but rather a system for creating a skin around and connective tissue between things like:
Demographic studies
Contextual inquiries
Stakeholder and user interviews
Surveys
The business ecosystem
Personas
Scenarios
Sketches, storyboards, wireframes
Mockups, models and prototypes
Email and IM conversations
Meeting notes
Content inventories and audits
Concept schemes, taxonomies, thesauri
A UI style guide
A branding and visual identity guide
A voice and tone guide
A code style guide
...etc
The individual elements of such a corpus represent the work of half a dozen specialist sub-disciplines, and are useful for realizing a product’s implementation. But if you hook them all up together, they merge to become a strategic artifact that transcends products and operates as a critical control surface for the business. This is because what such an artifact represents is a coral reef of deeply-considered and hard-fought decisions, and a story of the process that yielded them.