The individuals selected for this Mode could respond in two manners, either when the interviewer called them or in a second time by self-administered paper questionnaire (this was not mentioned on the phone).
For this mode five contact attempts are planned and it is the most simple Mode, as there is only one way the individuals can respond; by auto administrated paper questionnaire.
This mode contains the most complicated structure with seven contact moments and four different modes (or five if we include the NRQ). These four different modes are web, paper, CATI or CAPI and the non-response questionnaire.
The reserve group has only received the short version of the paper questionnaire i.e. the non-response questionnaire.
For more information see the Fiche Technique