1. ObservationObservation method refers to a method that researchers use their own senses and auxiliary tools to directly observe the object of study according to a certain research purpose, research outline or observation table, so as to obtain data. Scientific observation is purposeful, planned, systematic and repeatable.2. Literature research methodLiterature research method is a method to get information by investigating literature according to certain research purposes or topics, so as to understand and master the research problems comprehensively and correctly. Literature research method is widely used in various disciplines.3. Case study methodCase study method is a research method to identify a specific object in the research object, investigate and analyze it, and clarify its characteristics and formation process.