In non-response research, the researcher asks four questions: 1) Why did the approached person not respond? 2) Could this have been prevented? 3 Does this have an impact on the results and if so 4) Can anything be done about it?
No one is ever obliged to participate in an investigation. To find out why people do not respond, a non-response study must be conducted. In such a study, people who have not yet responded are approached again, but now with the question why they did not respond. Usually you hear reasons such as forgetting, not receiving, personal circumstances, no interest in the subject, too old, insufficient command of the language, etc. But if you hear from relatively many respondents that they do not like the researcher and therefore do not want to work , it becomes something else. Only by doing non-response research can you find out what is going on, otherwise it will remain a guess.
The reason why people do not participate always must be recorded. Only in this way can the researcher determine whether the response is selective and, if so, whether something can be done about this skewed response.