istrative records. It is important to evaluate the applicability and quality of the source(s) for the standards. Differences in 1990 and 2000 census procedures complicate the task of comparative evaluation, as do differences in survey procedures from census procedures.
Comparison of specific estimates from the census with the same estimates from other sources is another important form of data quality evaluation. For evaluation of the completeness of population coverage, the two traditional comparison sources have been demographic analysis and dual-systems estimation from an independent survey matched with a sample of census enumerations. For evaluation of the accuracy of such estimates as median household income, percentage multirace reporting, or the unemployment rate for specific population groups, comparison sources include household surveys, such as the Current Population Survey and the Census 2000 Supplementary Survey, and administrative records, such as Social Security records. The independent A.C.E. survey is also a comparison source for some estimates, such as people who reported more than one race.
Neither the census nor any comparison source can be viewed as the “truth,” and it can often be difficult to establish which sources, if any, may be “better” than the census. A careful assessment of the quality of each source is needed to help determine the relative superiority or inferiority of different sources used for comparisons with census estimates. Also, a careful examination of concepts and procedures for various sources and the census is needed to identify important differences that could affect the validity of comparisons of estimates.
An almost inevitable standard of comparison for a census is to compare its execution and outcomes—costs, timing, completeness of population coverage, and other criteria—with past censuses. Typically, the design for a census is shaped by perceptions of the major problems for the preceding census. However, differences in procedures and in the social and political context may affect the