Geographic Screening

Most surveys target a specific geopolitical area, so that estimates produced from their data can be representative of that area. For some surveys, the area consists of an entire nation, but other surveys aim to produce regional estimates (such as those for states, counties, or zip codes). Thus, such surveys require some sort of geographic screening, or determination that a sampled case falls within the target geography, to establish study eligibility. If the screening is inherent in the sampling design itself, no further information is required. Other studies require additional screening steps, either prior to sample release or during the field period. Decisions about the level of geographic screening for a study arise from the sampling frame to be used.

When the sampling frame for a ...