I found that many students complained that we didn't need to write any appendix at all, and some students said that I didn't know whether to write an appendix at all. Then I will introduce to the students under what circumstances students should write an appendix to their papers.

Do not include appendices that are not mentioned in the text. All appendices should be summarized in the papers related to the content, which is what I need to emphasize most.

The first point is that your paper needs to include these references in the body of the document, but it will seriously affect its structure or interrupt the process of elaboration;

The second point is that the references of the paper are too detailed and complicated to be summarized in the text of the paper, and they are very delayed in the text of the paper;

The third point is useful. There are many supporting materials, which will distract readers from the main content of the paper and make the paper look a bit strange. Provide relevant information or data that is easier to understand or analyze, which can be analyzed in the whole part of the paper;

Fourth, when the length of your paper is limited, you have to shorten your paper with an appendix;

The fifth point is that you provide an innovative thesis point, and further demonstrate your understanding of the research problem by providing additional innovative methods, technical details or details of the design agreement.

Finally, I suggest that students should not include vague or irrelevant information in the appendix; This extra information will not help readers fully understand and explain your research, but will only distract readers from understanding the overall significance of your research and reduce the academic quality of your paper.