Perceived Questionnaire Length
Posted by Jeffrey Henning on Mon, Nov 02, 2009
Back in 2002, Mirta Galešic of the University of Zagreb wrote an interesting paper that examined respondents' perception of questionnaire length, "Effects of questionnaire length on response rates: Review of findings and guidelines for future research". If objects in a side-view mirror are closer than they appear, then questionnaires appear to respondents to be longer than they actually are.
Galešic analyzed the relationship between objective and subjective questionnaire length. For objective length, she used the number of questions actually answered (to keep it simple, she treated each question as a question, regardless of its length or type). For subjective length, respondents were asked to rate the questionnaire they had just completed as «too short», «optimal», «somewhat too long» or «absolutely too long» (actual labels were in Croatian, as was the entire questionnaire). Not a single one of the 2,059 respondents answered «too short»!
Galešic writes:
Across all three questionnaire types there was an overall significant, but very small positive correlation between number of questions the respondents answered and their perception of questionnaire length (r=0.11, p<.01). Perceived length was more strongly correlated to the level of interest for the questionnaire topic (r=-.26, p<.01). The less interesting the questionnaire topic was, the longer the questionnaire was perceived to be. Level of interest for the questionnaire topic was not correlated to the number of questions answered (r=.03, p>.05).
Interestingly, however, respondents who had less interest in the topic judged the questionnaire equally long no matter how many questions were answered (the average number of questions answered ranged from 15 to 21 for each of the three surveys).
In the past I've provided six tips for shortening questionnaires. Thanks to this research, here's a seventh: Make the survey interesting to the respondent, and you will shorten the perceived length of the questionnaire.