The purpose of the Post-Enumeration Survey is to measure the accuracy of the census. The survey measures the accuracy of the census by independently surveying a sample of the population.
The U.S. Census Bureau has used post-enumeration surveys with dual system estimation to measure coverage in the Decennial Censuses of Population and Housing since 1980. This approach involves case-by-case matching of people in an independent survey with people in the census to determine who was missed or counted in error.
The post-enumeration survey-based coverage measurement program associated with the 2000 Census was called the Accuracy and Coverage Evaluation (A.C.E.).
The U.S. Census Bureau conducted the Accuracy and Coverage Evaluation (A.C.E.) survey to measure the coverage of the population for the 2000 Census. The A.C.E. was designed to serve two purposes: (1) to measure the net coverage of the population, both in total and for major subgroups, and (2) to provide data that could serve as the basis for correcting the census counts for such uses as Congressional redistricting, state and local redistricting, funds allocation and governmental program administration.
The Executive Steering Committee for A.C.E. Policy (ESCAP) reviewed the initial results of the A.C.E., which were released in March 2001, and recommended that unadjusted census data be used for redistricting as analysis and evaluations indicated that there were serious errors in these estimates. After assessing considerable new evidence, the second ESCAP Committee (ESCAP II) recommended, in October 2001, that unadjusted 2000 Census data also be used for non-redistricting purposes.
Research efforts to fix the detected errors resulted in improved coverage estimates referred to as A.C.E. Revision II which was released in March 2003. After extensive analysis and consideration, the Census Bureau ultimately decided not to use the A.C.E. - neither the March 2001 nor the Revision II results - to correct the 2000 Census counts or any other data products. A.C.E. Revision II, the superior of the two results, provides useful coverage measurement information that can be used for research purposes.
See Volume 2, Chapter 10