Keep it short!

 People seem to struggle with developing a research question and this struggle seems to get harder rather than easier the more advanced the degree. So, whilst undergraduates may think for a week or two about what they want to investigate, doctoral students tend to take months (or in some cases, years - yes Dr Fiona Duncan I'm looking at you!) before a simple, understandable research question is arrived at. This could be because many academics and students work on the theory that the cleverer something is the more complex and incomprehensible it has to be. I disagree - after all the most crucial questions in life are often the shortest - 'will you go out with me?',  'how can I help?' 'Is everything OK?' ''Do you want fries with that?' Even the BIG topics start with small questions 'Is there a God?' 'When will we understand the universe?' 'Why are doughnuts so yummy?' It seems as if the more important the question the more likely it  is that it can be communicated as a twitter message in 140 characters or less.
Big answers don't necessarily require big questions - just thoughtful ones