No. 264 · Evidence · Heuristics and Bias
Non-Response Bias
The people who stay silent can change the answer as much as those who reply.
In the Almanac
“The Hite Report”, 1987 · “Gallup”, 2012–2015
Both stories in full, three ways to use it and where it misleads.
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Questions
What is Non-Response Bias?
Non-Response Bias happens when the people who answer a survey, review or feedback form differ in important ways from those who stay silent. Even a well-chosen sample can produce misleading results if only certain kinds of people reply.
How do you avoid Non-Response Bias?
Whenever you rely on responses, ask who did not answer and why. Treat low response rates as a warning sign, follow up with quieter people directly, and look for patterns across many reviews rather than the loudest stories. Silence is data too.
When does Non-Response Bias matter?
Non-Response Bias is one of the 68 mental models for evidence, the situations where you ask: Is this really true? Within that, it belongs to “When research goes wrong”, alongside Anecdotal Evidence, Data Dredging and Hasty Generalisation.
What is an example of Non-Response Bias?
Two stories show it at work: The Hite Report (1987) and Gallup (2012–2015). Both are told in full in The Mental Models Daily Almanac, which has two stories for each of its 365 models.
Which mental models are related to Non-Response Bias?
Selection Bias, Churn and False Consensus Effect. Non-Response Bias itself comes from heuristics and bias.