Eligibility

Eligibility refers to whether or not a sampled unit is eligible to have data gathered from it—that is, is the unit part of the survey's target population or is it not? For example, the target population for a survey might be all adults who are 18–34 years of age. As such, if a household is sampled and screened via random-digit dialing and no one living there fits the age criteria, then the household is ineligible. If there is at least one person ages 18–34 years, then the household is eligible. Ultimately, eligibility versus ineligibility is central to the issue of how well a sampling frame and a sample drawn from that frame “cover” the target population and whether or not coverage error results. Eligibility also ...