第三，文献分析可以得到比口头调查更准确可靠的信息，可以避免口头调查中可

Third, literature analysis can obtain more accurate and reliable information than oral surveys, and can avoid various recording errors that may occur in oral surveys. Fourth, document analysis is an indirect and non-invasive investigation. Just survey and study the literature, without contacting respondents and without hindering responses. In doing so, you can avoid all kinds of reaction errors that may occur when the investigator is talking to the respondent.

Third, literature analysis can get more accurate and reliable information than oral investigation, and can avoid all kinds of recording errors that may occur in oral investigation. Fourth, document analysis is an indirect and non-invasive investigation. Just investigate and study the literature, do not contact the respondents, and do not hinder the answers. By doing so, we can avoid all kinds of reaction errors that may occur when investigators talk to respondents.

Third, literature analysis can obtain more accurate and reliable information than oral investigation, and can avoid all kinds of recording errors that may occur in oral investigation. Fourthly, document analysis is an indirect and non-intrusive investigation. Just investigate and study the literature, will not contact the respondents, and will not hinder the answer. In this way, we can avoid all kinds of reaction errors that may occur when investigators talk with respondents.