How do we find out what someone wants when they don’t know what they want or what they can have? One of the best techniques for gathering requirements is to interview users. But which users?

Imagine aliens came to the planet and offered to solve our gasoline problem. How could we tell them what we wanted? We might say we wanted cars that run on clean renewable energy. The aliens might leave thinking “Oh well, I guess they didn’t want faster-than-light travel.”