1, case study. Integrate theory with practice, and dissect cases to discover laws. Its characteristics are simple and easy to operate.

2. Field investigation or field trip. Go to the scene to interview and observe. Its characteristic is that it is easy to find new problems.

3. Questionnaire survey and statistical analysis. Through the distribution of questionnaires, statistical analysis, to find the law. The characteristic is that it can make up for the bias of case analysis and field investigation. The larger the sample, the stronger the universal significance.

4. Mathematical modeling method. Such as using game theory, structural equation model, system dynamics and other methods for calculation, reasoning and simulation. The characteristic is that it is easy to find various relationships and mechanisms in management.