no program to evaluate the completeness of population coverage in group quarters.

Recommendation 4.4: The Census Bureau must thoroughly evaluate and completely redesign the processes related to group quarters populations for the 2010 census, adapting the design as needed for different types of group quarters. This effort should include consideration of clearer definitions for group quarters, redesign of questionnaires and data content as appropriate, and improvement of the address listing, enumeration, and coverage evaluation processes for group quarters.

Finding 6.1: The 2000 Accuracy and Coverage Evaluation (A.C.E.) Program operations were conducted according to clearly specified and carefully controlled procedures and directed by a very able and experienced staff. In many respects, the A.C.E. was an improvement over the 1990 Post-Enumeration Survey, achieving such successes as high response rates to the P-sample survey, low missing data rates, improved quality of matching, low percentage of movers due to more timely interviewing, and substantial reductions in the sampling variance of coverage correction factors for the total population and important population groups. However, inaccurate reporting of household residence in the A.C.E. (which also occurred in the census itself) led to substantial underestimation of duplicate enumerations in 2000 in the original (March 2001) A.C.E. estimates.

Finding 6.2: The Census Bureau commendably dedicated resources to the A.C.E. Revision II effort, which completely reestimated net undercount (and overcount) rates for several hundred population groups (poststrata) by using data from the original A.C.E. and several evaluations. The work exhibited high levels of creativity and effort devoted to a complex problem. From innovative use of matching technology and other evaluations, it provided substantial additional information about the numbers and sources of erroneous census enumerations and, similarly, information with which to correct the residency status of the independent A.C.E. sample. It provided little