The aim of an intersectionality-informed survey of non-participants ("non-responder survey") is to gain information about the reasons for non-participation and about relevant social categories. 

A non-responder survey contains a necessarily short repertoire of questions in order to achieve the highest possible participation among the non-participants of a study and thus obtain a representative picture of the non-participants. For this reason, the questions for the survey must be selected with care. 

From an intersectional perspective, it is of high importance to obtain information on the age, sex/gender, socio-economic status and ethnic origin of non-participants. Other social categories can be added as long as this does not unduly increase the number of questions in the questionnaire. 

With regard to socio-economic status, for example, a question about the highest school-leaving qualification is suitable, as it is included in many health studies. In order to find out about ethnic origin, information on the country of birth of the respondent and the respondent’s parents can be collected, for example.

Non-responder surveys can also be used to request information that is not included in the census data, for example, through questions on language skills, gender identity or sexual orientation. Information on BMI is also relevant from an intersectional perspective, as body weight can be associated with discrimination.

Finally, reasons for non-participation can be collected. From an intersectional perspective, it is important to ask whether experiences of discrimination played a role in the decision not to participate. In addition, structural barriers to participation that are relevant in relation to individual categories of difference can be asked about. If the focus is on the difference category of sex/gender, then information on care work could be asked, for example, since caring for family members and children can limit the possibilities of participating in a study. 

Non-responder surveys can be used to obtain additional information from non-participants that is significant from an intersectional perspective. For example, specific reasons for non-participation, such as experiences of discrimination, can be collected. With the help of this information, measures can be derived to improve the opportunities for participation in a future study and to reduce existing barriers. 

The willingness to participate in a non-responder survey can also be low. If the participation rate in the survey is low, the result will not be representative of all non-participants. Therefore, care should be taken to ensure that the non-responder survey achieves the highest possible participation rate. Furthermore, a non-responder survey represents an additional effort for a study team beyond the actual survey programme.