Standard error reflects the fact that the MHS surveyed only a sample, rather than the entire population. Each sample selected for the MHS is one of a large number of similar samples that, by chance, might have been selected under the same specifications. Estimates derived from different samples would differ from each other. The standard error, or sampling error, of a survey estimate is a measure of the variation among the estimates from all possible samples and, thus, is a measure of the precision with which an estimate from a particular sample approximates the average from all possible samples.

Estimates of the standard errors have been computed from the sample data for selected statistics. They are presented in the form of relative standard errors. The relative standard error is equal to the standard error divided by the estimated value to which it refers. It is displayed in percent form (RSE times 100).

After 2015, RSEs are incorporated into the main MHS tables and not provided as separate tables.