-Experimental research: designing and executing experiments and collecting experimental data. This may include conducting experiments in the laboratory or in the field to collect quantitative or qualitative data.
-Questionnaires: make and distribute questionnaires to collect the opinions, opinions or experiences of the respondents.
-Literature review: search existing relevant research and data. This will help you understand the existing knowledge, determine your research field and find possible data sources.
-observation: according to a certain research purpose, research outline or observation table, use your own senses and auxiliary tools to directly observe the object under study, so as to obtain information.
-Interview method: communicate with the interviewee face to face or by telephone to obtain information and data.