"undeliverable" - 1 õppematerjal

Vormistamine ülesanne 3

For instance, in face-to-face surveys, noncontact can be the result of the inability of the interviewer to reach the respondent within the allotted number of contact attempts. Increasing the number of contact attempts not only increases the number of contacted and thus the response rate, but also the costs. Varying the days and times at which contact is attempted also increases the response rate, without affecting the cost as much. In mail and Internet surveys, noncontacts can be the result of undeliverable mailings due to errors in the address list. Tools to reduce refusals also depend on the data collection mode used. For instance, interview surveys may use specially trained interviewers to convert refusals, while mail and Internet surveys have to rely on incentives or special contacts to counteract explicit refusals. For more detail, see Lynn (Chapter 3). Nonresponse adjustment refers to statistical adjustments that are applied after the data are collected.