Error of Nonobservation

Errors of nonobservation refer to survey errors that are related to the exclusion versus inclusion of an eligible respondent or other sample record. This term principally refers to sampling error, coverage error, and nonresponse error. This is distinguished from errors of observation, which refer to errors that are related to the measurement of the content of surveys.

The term errors of nonobservation is based on the language and assumptions of survey methodology. It is similar to the concepts that psychometricians use to call the errors that impact external validity and, in some respects, is similar to what economists call "selection bias."

Within the total survey error perspective, errors of nonobservation can impact both random error and systematic error. Traditionally, however, coverage error and nonresponse error have been ...