AMERICAN COMMUNITY SURVEY:
SAMPLE DESIGN FOR COMPUTER ASSISTED PERSONAL INTERVIEW
Mark E. Asiala
Decennial Statistical Studies Division
U.S. Census Bureau
For presentation at the April 25-27, 2005 Meetings of the Census Advisory
Committee on the African American Population, the American Indian and Alaska
Native Populations, the Asian Population, the Hispanic Population, and the Native
Hawaiian and Other Pacific Islander Populations
What was the purpose of this research?
The purpose of this research was to devise a methodology to reduce the disparity in the
reliability of tract-level estimates from the American Community Survey (ACS).
What was the special interest in the reliability of estimates for tracts?
In general, tracts are small geographic areas with small populations. This makes
estimates for these areas more susceptible to variations in the interviewed sample which,
in turn, causes greater disparity in the reliability of estimates produced for those tracts.
While all surveys are affected by noninterviews which directly affects the interviewed
sample size, the design of the ACS adds another source of variation.
The ACS design has three modes of data collection, mail, Computer Assisted Telephone
Interviewing (CATI), and Computer Assisted Personal Interviewing (CAPI). Because of
the higher relative cost of personal interviewing as compared to mailing forms and
conducting telephone interviews, a 1-in-3 sub-sample is taken of those whose response is
not received by mail or CATI to follow up in the CAPI mode.
Tracts which have a higher proportion of their sample sent to CAPI will be impacted
more greatly by the 1-in-3 sub-sampling performed in the CAPI operation. The result is
that fewer interviews are obtained for the tract which leads to decreased reliability of
estimates produced for that tract.
What was the scope of this research?
The scope of this research was to identify tracts o