Checklist
Treat missing responses as an unanswered question
Silence is not a neutral rating waiting to be filled in.
When it fits
- Only part of an invited group completes a survey or follow-up.
When to avoid it
- A low response rate is a warning to investigate, not a numerical estimate of bias by itself.
Checklist
- Invitation, response and item-completion counts are distinguished.
- Known differences between respondents and nonrespondents are examined where appropriate.
- The conclusion acknowledges uncertainty that the missing responses create.
Why it matters
Report how many people were invited, reached and completed the relevant questions. Consider whether nonrespondents could differ in ways that matter to the result. Do not code missing answers as satisfaction, zero problems or agreement merely to make a complete table.
An example
People who stopped using a service may be less likely to answer its follow-up questionnaire.
Check your result
The report preserves missingness rather than silently converting it into a favorable outcome.
Keep this limit in mind
- A low response rate is a warning to investigate, not a numerical estimate of bias by itself.
Evidence and sources
Supports
Nonresponse can distort a result when respondents differ from missing participants in relevant ways.
A response rate alone neither proves nor quantifies the resulting bias.
Introductory Statistics 2e, 1.2: Data, Sampling, and Variation · Nonresponse