American Community Survey (ACS)

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Revised Estimates for Census 2000 Supplementary Survey and the 2000 American Community Survey

Limitations of C2SS Data

Differences Between the C2SS and the 1990 Census

Limitations of C2SS Data

Census sample data products, also known as census "long form data," are scheduled for release May - June 2002 [See Data Release Dates]. As the Census 2000 sample products become available they should be used instead of the C2SS as the best detailed description of the population and housing in 2000. The census sample data will be more reliable because they are based on a vastly larger sample - 19 million compared with 700,000 - and will be available for much smaller geographic areas.

The C2SS was an operational feasibility test of collecting census long form type data separate from the census. It is a part of the development program for the American Community, which is a planned replacement for the 2010 census long form. The C2SS and ACS ask essentially the same questions as the census long form, but there are some differences in results because of differences in reference periods and in how the data are collected. Also, group quarters are not included. The C2SS data products will continue to help researchers and other data users understand the ACS methodology and data products, although the C2SS sample is much smaller than the planned ACS.

Later in the year, data from the C2SS can be compared to results from the 2001 Supplementary Survey, to get information about changes in the characteristics of states and large cities and counties between 2000 and 2001 [See Data Release Dates].

For more in-depth coverage please take a look at the PDF document, entitled, "Preliminary Assessment of the Comparability of Census 2000 Long Form Estimates with Census 2000 Supplementary Survey Estimates" [PDF 32k].

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