aspects of data collection in the census, including data capture, the work of follow-up enumerators, the management of foreign language forms and foreign language assistance, and data editing and imputation for nonresponse.

The ACS has been mentioned as a possible survey vehicle for coverage measurement. We agree that there may be some potential for use of the ACS to help assess the quality of dual-systems estimation (DSE), or to help more broadly in coverage evaluation. However, some problems would need to be overcome in applying the ACS in this way. First, the address files for the ACS and the Census are very closely related, so at present the ACS could not be used to estimate whole household omissions. In addition, the ACS questionnaire is not focused on coverage measurement, as is that for the CCM. Finally, the ACS has a different defi-