It is estimated that over 40 percent of all persons contacted refuse to participate in surveys. Work to Make It Interesting. To gather completed interviews a questionnaire should be concise, interesting, and flow in a logical, clear-cut manner. Although a questionnaire is constructed at a person's desk or in a conference room, it is administered in a variety of situations and environments. Busy, or otherwise preoccupied, respondents will terminate uninteresting interviews.
Length alone can create a dull interview.
The researcher who is designing the questionnaire must not only consider the type of respondent but the interviewing environment and questionnaire length as well. By tacking on additional questions not related to the original purpose of the survey, two problems emerge. First, the interview becomes disjointed with topics coming in a dizzying array of unrelated topics. This destroys the flow and continuity of the questionnaire. The second problem is additional questionnaire length.