Close to the object of the investigation, if the investigator feels that the survey surveyed households, such as in the rest of the weekend or evening, investigators can say "we have the investigation need your cooperation, instead of saying" can not meet theunder our investigation? "or" Would you have the time? "may allow respondents said" no "questioning. The beginning of the household survey are at the door, investigators should try to shorten the greeting at the door, and managed to get into the house. Once the door, respondents are less likely to refuse to investigate.