For instance, a questionnaire may include questions about respondents drug use history, current earnings and sexual persuasions, many of the subjects in the sample may not answer due to the intrusive nature of the questions, but may answer all other items.
A questionnaire may include questions about respondents drug use history, current earnings and sexual persuasions, many of the subjects in the sample may not answer due to the intrusive nature of the questions. This is for instance. A questionnaire may include questions about respondents drug use history, current earnings and sexual persuasions, many of the subjects in the sample may answer all other items. This is for instance.