Word test results are the most accurate and close to the real situation, so word is used more when sampling. Because of the strong confidentiality of PDF format, it is difficult to convert it into format or edit it, so sampling inspection is rarely used. Sampling inspection of master's thesis after graduation refers to a measure to randomly select and re-examine the papers that obtained master's degree in the last academic year in order to prevent academic misconduct such as plagiarism and ghostwriting according to the regulations of the Ministry of Education.