Methodologically, there are levels of methods, and different levels of methods have their specific scope of application and applicable objects. When engaging in specific scientific research, researchers should first understand the characteristics, nature and research objects of their disciplines and research topics, and then choose corresponding research methods. For example, in the field of physics, there are some differences in the choice of research methods between theoretical physics and experimental physics. In short, in experimental physics, the first thing to consider is to obtain relevant data by observation and experiment, and then to process it by mathematical methods and statistical methods. Finally, the data are analyzed by model method and comparison method, and scientific conclusions are put forward. In theoretical physics, it is usually to establish a hypothesis, design a model, and then verify the hypothesis through hands-on experiments and ideal experiments. Of course, in the research process, besides, logical thinking methods such as thinking in images, intuition or inspiration, and systematic scientific methods such as system theory, information theory and cybernetics are also widely used. For example, in the practical research of sociology, we usually use sampling survey, interviews, questionnaires and other ways to obtain relevant information, then use statistical methods and classification methods to process the data, and finally deduce the model or draw substantive conclusions through mathematical methods. In foreign language research, due to the different research objects, corresponding measures have been taken. In the research of language use and language teaching, observation and experiment are often used for qualitative research, comparative research or descriptive research, while philosophical research adopts abstract and concrete methods, analysis and synthesis methods, the method of unifying history and logic, criticism and inheritance methods and comparison methods.