Research Tips

Nonresponse Bias

Nonresponse bias results when people who are selected to participate in research but don’t (because they decline to participate or cannot be reached) differ from those who do with regard to whatever is being investigated. The presence or absence of bias cannot be determined based on the response rate alone — it’s important to determine whether there is any likely reason to expect that the responses of those who didn’t participate would be different from those who did. For example, providing free products or services as an incentive for participating in a customer satisfaction survey may lead to nonresponse bias because those who are more satisfied could be expected to be more likely to want to receive free products or services (and therefore be more likely to respond) than those who are less satisfied.