On average it takes 7½ seconds to respond to an online market research survey question. If you keep the questions straightforward, you can ask eight of them in one minute.
However, of course most market research survey questions are not simple, and few of us can cram 80 questions into a 10-minute survey. Most market research surveys have a mixture of simple single choice questions, complex multiple-select questions, grid questions, open-end responses as well as numeric answers that need thought and mental calculation.
So the key to estimating market research survey length is knowing the equivalency of question-types vis-à-vis a prototypical short and simple question which takes just 7½ seconds to answer.
Why Does All Of This Matter?
As the cost of a survey – if you are doing it yourself or hiring an outside provider – is driven largely by time. The cost of designing, programming, testing, fielding as well as analysing data all depends on market research survey length. Finding respondents who are willing to participate, in addition to the incentives you need to pay them, depend on survey length also.
More crucially, how useful the data is to management could depend on survey length. Some surveys are too short and – when this happens – critical details go missing. Some surveys are far too long with so much data that you do not know what to do with it.
In addition, how good the data is may be dependent on survey length. Research demonstrates that data quality declines on surveys which are longer than 20 minutes. This means that a good rule of thumb is to aim for a market research survey that takes no more than 15 or 20 minutes to complete.