Sampling Frame
Definition
The list or description of all units from which the sample can be drawn. Any unit not on the frame cannot be selected, so coverage gaps in the frame directly produce coverage bias in the estimates.
- Definition
- List or description of all units available for selection
- Excluded units
- Cannot be sampled regardless of method
- Failure mode
- Coverage gaps produce coverage bias
Common questions
How is a sampling frame different from the target population?+
The target population is everything the study wants to draw conclusions about, while the sampling frame is the actual list or mechanism used to reach units for selection, and any mismatch between the two is the source of coverage bias.
What is a concrete example of a flawed sampling frame in forensic or criminological research?+
Using only closed and archived case files as the frame for a study on case outcomes would exclude currently open or sealed cases, so any conclusions drawn would not represent cases still in progress.
Can a good sampling method compensate for a poor sampling frame?+
No. Even perfectly random selection applied to a frame with systematic gaps will still exclude the same missing units every time, since randomness only governs who is picked from the list, not who appears on it.
Related terms
- Cluster Sampling
- A design in which the population is divided into naturally occurring groups called clusters, a random sample of clusters is selected, and...
- Gatekeeper
- A person or institution, such as a prison superintendent, police officer or community elder, who controls a researcher's access to a setting...
- Hidden Population
- A group with no enumerable sampling frame and a stigmatised or illegal status that gives its members an incentive to avoid being...
- Respondent-Driven Sampling
- A variant of chain referral, developed by Douglas Heckathorn in 1997, that tracks who recruited whom and each respondent's network size so...
- Sampling Bias
- A systematic distortion in an estimate caused by a selection process that does not give all units a known probability of inclusion....
- Sampling Error
- The difference between a sample statistic and the true population value, arising from the randomness of selection. It can be estimated from...
- Selection Bias
- A distortion that arises when the group being studied is not a random sample of the wider population; in Neighbourhood Watch research,...
- Simple Random Sampling
- A design in which every possible subset of a given size has an equal probability of being selected. It requires a complete...
- Snowball Sampling
- A chain-referral technique in which each recruited respondent is asked to name or introduce others who share the trait the study is...
- Stratified Sampling
- A sampling design that divides the population into homogeneous subgroups (strata) and samples each stratum separately. Allows the auditor to apply higher...
Explained in these topics
- Sampling and Fieldwork with Hard-to-Reach PopulationsThe list or set from which a sample is actually drawn, such as a prison register or an electoral roll; hidden populations have no such list, which is the core...
- Sampling Strategies and Representative Data