Is the 2000 Census the first time statistical sampling procedures will be used?
A. No! Since at least 1940, statistical imputation has been used when an enumerator knew that a housing unit was occupied, but could not obtain information on the number of people living in that unit. Sampling statistical procedures were used to add persons to the 1970 Census. The 1970 Census included about 4.9 million persons who were added on the basis of various statistical procedures including sampling. For example, a recheck of a sample of housing units labeled vacant, revealed that about 11.4 percent of the housing units originally classified as vacant were really occupied. As a result, about 1.1 million persons were added to the count using statistical procedures.
