Getting effective user feedback is never easy, particularly when potential choices go wider than the user’s experience.  Kathy Sierra explores how to do it:

So how can we hope to learn anything about what our users want and need if the very act of answering a question could change their answer? We have to get better at making inferences from what we observe without intervention. We have to get to the spirit of what we observe, rather than focusing on the specific details. We have to recognise that what they do says much more than what they say, especially when they’re not saying anything at all.

People give different answers depending on how they are asked the question and how they are asked to provide the answer.  Earlier notes on some other material covering the wider point that ‘they don’t know what they want when they don’t know what’s possible’ are here and here.