“Based on 1,000 responses” tells you how many answers were analysed. It does not tell you how many people were approached or how the participants were selected. A response rate addresses part of that missing context, but it needs a definition before the percentage becomes useful.
The American Association for Public Opinion Research’s response-rate guidance provides standard definitions because real surveys include more than completed interviews. Eligibility, partial responses and cases whose status is unknown can affect the calculation.
Imagine a clearly defined group of 2,000 eligible invitees, of whom 1,000 complete a questionnaire, with no other complications. The straightforward completion fraction is 50%. If the same 1,000 completions came from 10,000 eligible invitees, it would be 10%. The analysed sample size is identical, but the participation context differs.
Actual published response rates may use a more detailed standard formula. Look for that formula or methodology note rather than attempting to reconstruct it from an advertising headline. An open online poll may not have a known set of eligible invitees at all.
Ask what happened to the people who did not respond
A low rate raises questions about whether respondents differ from nonrespondents in ways relevant to the subject. It does not, by itself, quantify the error in a particular result. A high rate also cannot repair a sampling frame that omitted an important group.
- Who was eligible and how were they contacted?
- Which response-rate definition was used?
- Were follow-ups or adjustments made?
- What limitations does the researcher acknowledge?
Keep sample size and response rate in separate notes when comparing surveys. One describes the amount of response data; the other helps explain participation in its collection. Neither deserves to carry the whole argument about whether a result is trustworthy.