When I worked with James Bach on a Satisfice project he would ask me uncomfortable questions about what I was doing and why I was doing it. He’d ask, “Tell me what this bug is at its core.” I’d say, “When I click this button, I get an error message instead of the dialog I’m expecting.”

“Why do you expect a dialog?”

“Because that’s how the app is supposed to work.”

“How do you know?”

“It worked that way another time.”

“Ahh, so there is an inconsistency between how it worked before and the way it works now. What is different? How do you know that they are not both right?”