The selected respondent is the one whose birthday was most recent. Another is the Troldahl-Carter method, which uses a set of forms with matrices for the selection of the oldest male, youngest female, etc. Another asks for respondents to be listed in order of age and uses a random number list to select which one is interviewed. This technique does not require the listing of potential respondents by name, nor does it require asking for their birthdays, which can sound invasive to some people. Most typical is two callbacks to reach a household and another two to complete an interview with the correct respondent.
Callbacks are the only way to achieve such a rate.
Various studies have investigated whether people reached on the first call differ from those reached on the second or third call. There are differences. Machine households are no more likely to refuse than non-machine households. F. CATI Sample Management Many CATI systems have sample management built in. The sample is provided on tape or disk.