Required reading: Gause and Weinberg show how to ask for what you want -- "Their breadth helps too: their chapters cover everything from holding effective meetings to scoring client preferences to measuring ambiguity. Context also plays a role: Gause and Weinberg always explain why their preferred solutions work better." (Comments: I know Don Gause personally since he is one of my Ph.D. advisors. It just so happens that my research area is requirements engineering. Have you seen my Requirements Engineering Portal?)