Step 1: Determine how many questions to pose (I).

(I) = instrument example

Include enough items to indicate a seriousness of purpose but not so many items that they overburden the respondent. Although research indicates that shorter questionnaires usually generate higher response rates, questionnaire length by itself probably isn't as important as other factors we will discuss. There is little benefit to shortening an already short questionnaire (say, reducing 8 items to 4 items), because this may signal that the task isn't very important. Reducing an 80-item questionnaire to a 40-item questionnaire may improve the response rate, but the difference is not likely to be huge (perhaps a gain of 10-15% more respondents). There is some evidence that respondents balk at questionnaires that exceed 100 items.