You're on your lunch break and you decide to open your inbox and browse through some emails. That's when you notice a message from the company that you just purchased a TV from. The company's customer service team wants you to fill out a survey assessing your shopping experience.
Feeling generous, you decide to participate. But as soon as you open the link, you realize the form is 50 questions long with 20 open-ended answers. Shaking your head, you exit the page and delete the email.
For many SMBs, cases like these are far too common. Survey length can make or break a survey and finding the right balance is difficult for some companies. If your surveys are too long, participants won't complete them or won't even bother to take them. If they're too short, your team will miss opportunities to gain insights into your customer base.
The tricky part is, there are no hard-and-fast rules on survey length. It's dependent on your industry as well as your target audience. This is where businesses need to experiment to find the length that's right for them.
In this post, let's explore survey length and analyze some studies that explain how long your surveys should be.
In general, when there are more survey questions, participants answer quicker than they would with shorter surveys. Faster responses mean less attention to detail, which jeopardizes the accuracy of your findings. So, it's important not to ask more questions than are absolutely necessary for answering research questions.
A good rule of thumb is to consider your target audience and when they'll be taking the survey. Think about how much time they'll be willing to volunteer for this activity and take note of the difficulty for each question. The harder the question is, the more time it'll take to complete. For most companies, the ideal number of questions you'll want to include is less then 30.
A couple of sources have tested this theory to determine an ideal survey length. Read on for their results.
How Long a Survey Should Be, According to 2 Studies
SurveyMonkey took a random sample of about 100K surveys ranging in length from one to 30 questions. It analyzed the average time it took each respondent to complete the survey and placed the results in the chart below.
As you can see, as question count increases the average seconds spent per question decreases. That doesn't mean that longer surveys will always provide quick answers as there are other factors that can affect this data -- type of survey, the importance of the survey, target audience, etc. However, as shown below, the average time spent on each question in surveys longer than 30 questions is almost half that of surveys with fewer than 30 questions.
Additionally, with surveys that took longer than seven or eight minutes to complete, completion rates dropped by five to 20%. And, these completion rates were lower for customer-related surveys versus school or work surveys. Keeping this data in mind, it's best to have a survey that's less than 30 questions and/or takes less than 8 minutes to complete.
2. Insights Association
The Council of American Survey Research Organizations -- which has since merged with the Marketing Research Association to form the Insights Association -- held a webinar series where Inna Burdein Ph.D. conducted a study on survey length and effort.
She created an experiment with the following five types of surveys, ranging in length and difficulty:
She ranked difficulty on a variety of conditions, such as ratings (easy) versus rankings (difficult) and agree or disagree (easy) versus pick one statement (difficult). These conditions helped her construct surveys in varying levels of difficulty, which then elicited the following results:
As you can see, survey difficulty, and not just length, affected completion rates. One can presume that it's the difficulty of a survey that causes abandonment more so than length, since a survey of 24 easy questions has an 89 percent completion rate, while a survey of 24 difficult questions has an 82 percent completion rate.
Keeping this in mind, it might be better to simplify your survey before cutting its length. As shown in the SurveyMonkey research, it's better to maintain a survey with less than 30 questions. This way, you can incorporate some difficult questions among your easier ones to garner more interesting insights without having a large impact on your completion rate.
Now that you know how long your survey should be, it's time to decide on survey questions.