Errors of Omission

Errors of omission are also sometimes called "false negatives." They refer to instances in which someone or something is erroneously excluded from consideration when they or it should have been included. In survey research, this error typically occurs when the eligibility of a unit is determined. For example, when someone is screened at the start of interviewer contact to determine whether or not he or she is eligible, and the person answers erroneously in a way that keeps the interview from proceeding as though the person were ineligible for data collection when in fact the person is eligible, this is an error of omission. In these cases, data are not gathered from someone who should have been interviewed.

Errors of omission occur for many reasons, but ...