间接观点表述:
Through observation study, you can just watch and take notes. And you can get some unforeseeable results from people's behavior, but it can only cover certain aspects. Therefore, you need other research method to assist it. But you can try if you want.------中立
Well, I think questionnaires are very good at telling you how people fill in questionnaires, but they tell you very little else. So better avoid it.------反对
Face-to-face interview can help you get people's facial expressions and body language, through which you can identify what they genuinely have in mind. But it depends sometimes. Not everyone is willing to open his or her mind to you.------中立