Definition: Coverage error
Error in an estimate that results from failure to include specified units (“Units” are the objects of interest of the survey, i.e. the individuals, households, enterprises, etc.) in the conduct of a survey (undercoverage), and inclusion of some units erroneously either because of a defective frame or because of inclusion of unspecified units or inclusion of specified units more than once in the actual survey (overcoverage).
United States Department of Commerce, Bureau of the Census, “IT Standard 16.0.0: Survey Design and Statistical Methodology Metadata”, draft (never officially published), August 1998