What is a sampling frame, and why can frame mismatch bias occur?

What is a sampling frame, and why can frame mismatch bias occur?

• A. A sampling frame is the actual list from which a sample is drawn; mismatch with the population causes coverage bias and generalizability problems.
• B. A sampling frame is only theoretical.
• C. Frame mismatch improves accuracy.
• D. Frame mismatch only affects experimental studies.

Answer: (A)

A sampling frame is the actual list you use to draw your sample—the practical link between the population you care about and the data you collect. If this frame doesn’t represent the population, frame mismatch bias can creep in. When parts of the population aren’t included in the frame (undercoverage), those people are less likely to be selected, so their characteristics are underrepresented. If the frame includes units that aren’t in the population or contains duplicates or outdated contacts (overcoverage or miscategorizations), the sample can overrepresent some groups and underrepresent others. Either way, the sample won’t mirror the population, which harms generalizability and can bias estimates. For example, using a landline directory to study city adults tends to miss younger or cell-phone–only households, skewing results. The frame is not merely theoretical; it’s a concrete list used in sampling, and issues with it are a common source of bias across survey designs, not something that would improve accuracy or be limited to experiments.

A sampling frame is the actual list you use to draw your sample—the practical link between the population you care about and the data you collect. If this frame doesn’t represent the population, frame mismatch bias can creep in. When parts of the population aren’t included in the frame (undercoverage), those people are less likely to be selected, so their characteristics are underrepresented. If the frame includes units that aren’t in the population or contains duplicates or outdated contacts (overcoverage or miscategorizations), the sample can overrepresent some groups and underrepresent others. Either way, the sample won’t mirror the population, which harms generalizability and can bias estimates. For example, using a landline directory to study city adults tends to miss younger or cell-phone–only households, skewing results. The frame is not merely theoretical; it’s a concrete list used in sampling, and issues with it are a common source of bias across survey designs, not something that would improve accuracy or be limited to experiments.