What is Frame Error?
A frame error (also called coverage error) happens when the list or method you use to reach people (the sampling frame) doesn’t match the group you want to learn from (the target population), causing some people to be left out or the wrong people to be included. This mismatch biases results and can mislead decisions.
A sampling frame is the roster, database or channel you use to invite or contact respondents — for example, an email list, a school register or a street-by-street address list. A frame error occurs when that frame does not accurately represent the target population. Common causes include outdated contact lists, excluding people who don’t use the chosen channel (e.g. phone vs. online), or using sources that systematically miss specific groups (for example, migrants, renters, people who don’t speak the dominant language). The result is that some communities are under‑ or over‑represented, which skews findings and reduces the credibility and fairness of your survey.
Usage example
A council wants feedback from all residents but sends the survey only to property owners using a council tax database. Renters and people who live in subsidised housing are largely absent from responses — a frame error that misrepresents community views. Similarly, sending invitations only in English can create a frame that effectively excludes non‑English speakers.
Practical application
Why it matters: decisions based on surveys with frame error can systematically overlook the needs of excluded groups — leading to poor policy, unequal services or unfair allocation of resources. For organisations aiming to reach multilingual communities, frame error is a practical risk: even a perfectly translated survey won’t help if the people you need to hear from aren’t in your contact list or can’t access your chosen channel. How to reduce frame error: check whether your frame covers the populations you care about; use multiple contact channels (email, SMS, paper, in‑person); partner with community organisations; collect minimal demographic and language preference data to assess coverage; and document limitations so stakeholders understand who was reached. Hearo helps on the accessibility side (one survey, many languages, translated responses), but you still need inclusive outreach and an appropriate sampling frame to avoid frame error.
FAQ
How is frame error different from nonresponse bias?
Frame error (coverage error) is about who is reachable in the first place — missing or extra people in your contact list. Nonresponse bias happens when people in the frame don’t respond and respondents differ systematically from nonrespondents. Both bias results, but frame error is fixed by improving the frame; nonresponse bias is addressed by boosting response rates and adjusting analyses.
Can better translation or multilingual surveys eliminate frame error?
No — good translations reduce language barriers for people who receive the invite, but they don’t help if those people were never included in the frame (for example, because contact details were never collected). Translation and multilingual access are necessary but not sufficient: you still need outreach channels and lists that cover the communities you want to hear from.
How can I check if my survey frame is missing important groups?
Compare the demographics and language profiles of your frame against known population or administrative data (census, school lists, service records). Look for gaps in age, geography, tenancy, ethnicity or language. Use a short intake question (e.g. postcode and primary language) to spot underrepresented groups and adapt outreach or use targeted sampling to fill gaps.