How Many Questions in a 10-Minute Survey?
It all depends on what counts as a “question,” and also on how complex those questions are. A grid question with multiple rows takes a longer to answer than a simple yes-or-no question. A question that allows you to select multiple items from a laundry list of options takes longer than a standard 4-point scale. Ranking, in order, the top three to five items from that laundry list will take even longer.
Not that anyone is vying for the prestigious honor of being a survey-timing-guru, but we did feel proud to discover that Versta Research is now cited in the Federal Register as providing authoritative guidance on survey length. A notice filed by the Department of Transportation in Vol. 81, No. 193, October 5, 2016 says:
The estimate time for survey completion was calculated using Versta Research’s methodology for calculating an estimate of survey length, where each question is given a number of points based on the estimated burden required to respond to the question (for example, simple multiple choice questions are 1point, whereas short answer questions are 3 points per expected short phrase). The total number of points for all questions is then divided by eight (the number of simple questions a user can respond to online in 1 minute) to determine the estimate required length for finishing the survey.
You can find the details of our method in the Versta Research Winter 2011 Newsletter. Basically, each simple question takes 7½ seconds, so the trick is to translate all the standard question-types (many of which are not simple) into a number “points” that are simple-question equivalents. The method is easy to learn and easy to implement. Once you get the hang of it, it becomes second nature and you’ll know the length of any survey you write in just a few minutes.
That being said, and knowing that all the different question types tend to average themselves out in most of the surveys we write, here is what we generally proffer as the number of questions you can ask in a survey:
5 minute survey: 10 to 15 questions
10-minute survey: 20 to 30 questions
15-minute survey: 30 to 45 questions
If you take a look at the DOT’s Federal Register entry you will also note they used our method to estimate that their survey would take respondents about 2 hours and 12 minutes to compete. Yikes! Unless you are surveying government officials who are well paid and required to fill out informational surveys like this, don’t try this at home. For most surveys, 20 minutes is about the maximum you can go before respondent attention lags and data quality deteriorates.