How do you politely say, "Your mental representations are so messy and imprecise I'm having trouble categorizing what you need?" You say: "OK, now that we've c

How do you politely say, "Your mental representations are so messy and imprecise I'm having trouble categorizing what you need?" You say: "OK, now that we've covered the standard flow, let's talk about the strange cases. What are the weird situations that come up once in a while?" For many users, "ALWAYS" translates to "always, except for the oddball case", and "NEVER" translates to "not usually, but you never know." That's why Requirements Analysis is as much about psychology and anthropology as it is about logic.