How to ask a good question?

Which one is more important:
Ability to answer question?
Or
Ability to ask a good question?

With Internet portal such as google, yahoo, and wikipedia, we can find (most) of the answer on the internet. However, not everytime we get the answer we are looking for. Forum, could be another solution to ask to the expert and get the answer. But, have you in the situation when no one replied you in the forum. The reason is simple, we don't know how to ask a good question? Or could it be because we are not familiar with the subject that we ask for.

Education system teach us to answer question. Our grade is base on how we answer those question or how we derive to get those answers. Is it possible that in the future our grades will be based on our ability to ask a question?