Its advantages are: respondents can express their opinions truthfully, and are not affected by other factors, especially when investigating sensitive issues, more reliable information can often be obtained; Because of the use of standardized words, the problems faced by each respondent are exactly the same, so there is no subjective interpretation and induction of the questionnaire by the investigator, which avoids the bias of the investigator.

Its shortcomings are: if the answers in the questionnaire are vague or refuse to answer some questions, it is difficult to remedy; It is impossible to know whether the respondents independently completed the questionnaire and the environment for answering questions, thus affecting the judgment of the quality of the questionnaire.