Out of Sample

The out of sample survey disposition is used in all types of surveys, regardless of mode. Cases with out of sample dispositions are considered ineligible and are not contacted again. As a result, the out of sample disposition is considered a final disposition.

In a telephone survey, out of sample dispositions usually occur when the telephone number dialed by an interviewer rings to a household, business, or individual that is outside of the geographic sampling area for a survey. For example, in a random-digit dial (RDD) survey of the general public, this is most common when the survey is sampling relatively small geographic areas such as counties, towns or villages, or neighborhoods for which telephone prefix boundaries do not conform exactly (or even closely) to geopolitical boundaries. Out-of-sample cases usually are discovered only if the questionnaire for the telephone survey includes screening questions that verify that the respondent or household is located within the geographic area being sampled for the survey.

In an in-person survey, out-of-sample cases include ineligible housing units that were listed as being within the sampling area but actually are outside of it. Out-of-sample cases in these surveys also can include other households or businesses that were incorrectly included in a list sample—any unit that is not properly part of the target population for the survey.

In a mail or Internet survey of named respondents, out-of-sample cases occur when the named respondent is found to be ineligible to participate in the survey based on screening information he or she provides on the questionnaire. For example, a respondent who indicates that he or she is not a doctor would be considered out of sample in a mail or Internet survey of physicians.