After asking you about your qualities, expect them to ask you about the areas you feel you need to improve. You are not telling them that you are weak or terrible, but you are admitting there are things you could strengthen. This is not the time to air your personal laundry. Choose one or two items, state them and state how you are working to improve them. If you don't mention anything, then you are portraying yourself as being perfect and the panel will feel that you are not being truthful.