A market research questionnaire should be as short as possible while – at the same time – ensuring that the researcher is able to gather valid and reliable answers to all questions that are asked of each respondent.
Questionnaire length, which is often referred to as length of interview or “LOI,” is usually measured by the average time that it takes a respondent to finish the whole questionnaire when it is administered in a comparable context to that in which it will eventually be fielded.
There is no objective limitation on how long a questionnaire may be, nor any definite maximum number of questions which it may contain. The mental burden that a questionnaire puts on a respondent will vary not only based on the individual respondent however also based on how the questionnaire itself has been created, what kinds of questions it contains as well as how and when it is administered, and many other factors.
The Psychology Behind Survey Questionnaires
In general, when there are a lot more survey questions participants tend answer quicker than they would with shorter surveys. Quicker responses mean less attention to detail, which jeopardises the accuracy of your findings. This means that it’s important not to ask more questions than is utterly required for responding to research questions.
A good rule of thumb that you should follow is to consider your target audience as well as when they’ll be taking the survey. Think about how much time that they’ll be willing to volunteer for this activity and also take note of the effort required for each question. The more difficult that the question is, the more time it’ll take to complete. For most organisations, the ideal number of questions you’ll want to include is less than 30.
What Should You Consider When Writing A Market Research Questionnaire?
While there are no hard-and-fast rules governing market research questionnaire length, there are a number of general guidelines that good researchers tend to keep in mind when putting together questionnaires for ordinary market research contexts.
These regulations take into account the fact that because as questionnaire length increases, the ability of respondents to offer valid and reliable responses to each question decreases.
At the same time, response validity (i.e., data quality) ultimately deteriorates to the point that any further questions asked of the respondent are not worthwhile as the individual’s attention span and ability to provide valid answers has been utterly exhausted.