There is no doubt that surveys are the most important thing in the world of customer experience and research. In one look, you would think that it is just a couple of questions that need to be answered probably as an MCQ or an open-ended question. However, it isn’t that simple! In fact, it’s just the tip of the iceberg. There are a lot of underlying aspects to a survey. You need to ask the right question at the right time to the right set of audience. Once the survey is sent you need to collect the responses and analyze them in the right way to come to a conclusion and make the right decisions.

Speaking of response analysis, it is not just about grouping them as per the different answers. One needs to screen the biased responses and even non-responses. Yes, you heard it right. There is something called non-response bias as well and you need to watch out for such a thing if you want to leverage the best results out of your survey.

We are here to help you. In this article, we will be discussing everything a survey maker should know about non-response bias. So, first and foremost, let’s find out what this nonresponse bias is.

What is Nonresponse Bias?

Nonresponse bias can be defined as the inability or unwillingness of a participant to respond to a survey or complete it. Evidently, the participants who come under this category will have reasons that largely differ from those who actually filled out your survey. Nonresponse bias can be the result of a lack of clarity in questions, undesirable questions, lengthy surveys, or simply unwillingness as mentioned before.

This is definitely a pressing issue for researchers and businesses because they lose out on potential respondents who could have actually increased the survey response rate to make the insights much richer and more reliable. 

Now, you should keep in mind that response bias and nonresponse bias are entirely two different ideas. Though it is evident from the name itself, people still tend to have a mix-up when it comes to biases in surveys. So, let’s clear it up once and for all.

Response Bias vs Nonresponse bias

As their names indicate, nonresponse bias is associated with people who don’t respond to your survey or leave your survey midway, whereas response bias is associated with participants who respond to your survey.

While nonresponse bias demands the interviewer to dig deep into the reasons behind the participant neglecting the survey, response bias looks into the reasons behind inaccurate or untruthful answers. For example, if the interviewer constructs the question in such a way that the respondent is forced to answer in a favorable manner, then there is a chance of response bias. Now, if the question is quite personal, it could intimidate the respondents and they might quit the survey. This is an example of nonresponse bias. Also, please note that even if the participant decides to leave a particular question unanswered, it too serves as an example of nonresponse bias.

What are Factors that Cause Nonresponse Bias?

There are a handful of factors that lead to nonresponse bias. As a business, or a research team trying to overcome it, you will first need to know the root causes of nonresponse bias.

1. Mediocre and Careless Survey Construction

Construction is the aspect that makes or breaks your survey. The reason is why have to put a lot of thought, research, and time to create surveys. There are a few fundamental rules for constructing surveys. Firstly, the questions ought to be clear and to the point. Secondly, the survey should not be lengthy. Studies have observed a 5-20% drop in completion rates if the survey time exceeds 7 minutes. Thirdly, maximize close-ended questions and only include open-ended questions if it is truly necessary. Effectively, your surveys ought to be user-friendly.

2. Targetting the Wrong Audience

Make sure you conduct enough research to find the right audience. One small error in targeting can lead to a huge difference. For example, sending a survey about wallets to an audience that predominantly consists of women might not help you get enough responses. So, it is imperative to target the right audience.

3. Asking Sensitive Questions

Let’s suppose you have questions in the survey regarding therapies. You ask if the respondent takes therapies and the respondent replies in the affirmative and the following question pry about the discussions in their therapy sessions. Now, that’s not really the kind of question you should be asking especially if the survey is not anonymous. The respondent might not be comfortable answering such questions as it is quite intrusive. When that’s the case, you are bound to receive a nonresponse bias.

4. Not Pre-testing your Surveys

Sometimes, businesses and researchers send their surveys straight to their audience without testing them amongst themselves. You could miss out on a question, there might be broken links, or the design might not be mobile-optimized (a huge section of the young respondents use their mobiles). All this can put off the survey participants, eventually leading to nonresponse bias.

5. Leaving Out Questions by Accident

Everyone has some commitments in their daily lives and surveys aren’t their priorities. However, with relevant and engaging questions and designs, you can keep your respondents hooked to your surveys. But again, there’s a catch. There are chances of participants forgetting to answer questions or leaving surveys midway due to other distractions. Well, you can’t do much about such situations.

Examples of Nonresponse Bias

Now, let’s explore some day-to-day examples of nonresponse bias.

Example 1

Let’s say you send a survey to a group of customers after a good gap of a whole year. You have all their contact details recorded in a CRM but haven’t tried to update the list for a year. You send the survey and notice that your delivery and open rates are much lower than you expected. Now, you delve into the reason and find out that many of your customers have changed their email addresses. This is an example of nonresponse bias because the customers didn’t attend your survey even though the surveys were sent to them.

Example 2

Suppose you run a social media platform along with the likes of Facebook and Instagram. You decide to conduct a survey about the platform experience. Having only a few initial users, you ask for their passwords to get a better idea of how the platform works for each user. However, upon sending the surveys you find out that the response rates are extremely low. You even get complaints from your users calling out on the inappropriateness of the question. This is another classic example of nonresponse bias. These questions might help you get a better perspective, but they are extremely sensitive and it is quite important to respect people’s privacy.

Why is Nonresponse Bias a Problem for Researchers and Businesses: The Disadvantages

Evidently, nonresponse bias is not something that is welcome by researchers and businesses. Here’s why:

  • Nonresponse bias leads to a lot of variations in the research and the interviewer/researcher might end up with smaller sample size. 
  • It reduces the reliability of a survey result as it affects the response rate and can therefore mislead the learnings of research.

How to Avoid Nonresponse Bias: 7 Super-effective Ways

Here are 6 of the most effective ways to optimize your surveys to avoid nonresponse bias and increase your survey response rates.

  1. Keep your Surveys Short and Concise
  2. Provide an Incentive
  3. Remove Double Barrelled Questions
  4. Convey the Goal of the Survey
  5. Time and Distribution
  6. Send Reminders
  7. Close the Loop


1. Keep your Surveys Short and Concise

Create surveys that are short and are to the point. Your questions ought to be relevant and should talk clearly about their intent. Beating around the bush with long introductions will not work here. As survey makers, it is important to understand that we live in a fast-paced world and your respondents do not have all day to spend on surveys. Moreover, the attention span of a person has decreased from 12 seconds in the 2000s to the current average of 8 seconds. You need to keep all this in mind while creating surveys. So, do create short surveys, preferably with close-ended questions.

2. Provide an Incentive

Offering incentives can be a great way to ensure the success of your surveys. Here’s what you can do. Offer a coupon, discount, or simply a gift card to participants who will fill out the entire survey. It is also a way of telling your respondents that you value their precious time and is thankful for it. This is surely going to motivate the participants to complete the survey.

However, there’s a catch. A lot of incentives could lead to biased responses. Respondents might end up filling your survey just for the sake of receiving those gifts and can answer it randomly or give only positive responses. This might skew your survey results. So, offer the right incentives and make it clear to the respondents that you are looking for genuine answers be it positive or negative.

3. Remove Double-Barrelled Questions

Ever heard of the double-barrelled questions? Let’s see what it is then. Double-barrelled or double-direct question are those that ask effectively two questions at the same time but accepts only one response. These kinds of questions are very confusing and can urge the respondents to opt out of the survey. Here’s an example of a double-barrelled question:

How satisfied are you with your pay and work timings?”

  • Completely Satisfied
  • Dissatisfied

Now, this question asks about two aspects of your job, which are pay and work timings but limits the scope of your answers. Chances are that you could be satisfied with your payment but not your work timings and vice versa. However, here you are allowed to be either satisfied or dissatisfied with both, which makes the survey lose its meaning. Also, the confused respondents might choose to not answer such questions. So, avoid double-barrelled questions at all costs.

4. Convey the Goal of the Survey

Informing the objective of your survey to the respondents can go a long way in boosting your survey response rates. Survey participants always appreciate transparency, especially at times when people are increasingly concerned about their privacy. So, convey the goal of your survey at the beginning. Also, inform that you are complying with the security standards with the help of an online survey maker and their details will not be compromised at all. This will definitely encourage your respondents to fill out the survey.

5. Time and Distribution

Time and the channel of distribution can play a crucial role in defining the success of your surveys. You need to choose the right time to distribute the surveys through the right channel.

Let’s say, you have a target audience who has 9-5 jobs. You plan to send them a survey at 9:30 in the morning via Whatsapp. Think it will work out? It’s a definite NO! It’s the peak time at most workplaces and nobody’s going to answer your surveys, and definitely not through Whatsapp!

Hence, the importance of timing and distribution. So, make sure you share your surveys at the right time through the right channel.

Pro Tip: Find the average time a person will take to complete your survey and inform your respondents of the same at the beginning of the survey. This way they know how much time they should invest once they start the survey. When that’s the case, the number of people leaving the survey because of its duration will be comparatively low.

6. Send Reminders

We tend to forget things and the same goes for your respondents as well. As mentioned earlier, sometimes respondents forget to answer your surveys or can be completely unaware of such a thing, which can lead to nonresponse bias. To minimize such issues, you can send gentle reminder emails to your respondents. According to studies, reminder emails have the potential to boost response rates by 36%. 

But do not overdo it. Sending too many reminders is the last thing you want to do! It can put off your potential respondents and they might even end up unsubscribing from your list. So, make sure that you do not send more than 3 reminder emails and keep fixed intervals in between them.

7. Close the Loop

Last but not least, close the loop! You can send surveys, and collect ample responses but if you do not take the right measures to heed customer opinions, then you are in for some trouble. 

Customers leave their feedback in the hope of getting their issues fixed, despite their busy schedules. If you do not take the effort to address their issue and resolve them, then you are disrespecting their time. Once the customers realize that their voice is not being heard, they will refrain from filling out your surveys in the future.

Yes, we understand that closing the loop can be a hectic process, but you cannot evade it. Thankfully, the market has customer feedback tools like Affiniv that are available at very affordable rates. They let you send surveys, collect feedback, analyze them and take the right actions to close the loop.

Final Note

Biases can’t be completely erased from your surveys, but they can be reduced to a great extent if you make an effort. The first step will be to make a plan and then follow a set of processes to avoid both response and nonresponse bias. Using a survey tool can expedite such processes by increasing efficiency and reducing time. So, let’s sign up for a free survey tool and start planning already!