Census Tract Program for the 2010 Decennial Census-Final Criteria
Census tracts are relatively permanent small-area geographic divisions of a county or statistically equivalent entity \1\ defined for the tabulation and presentation of data from the decennial census and selected other statistical programs. Census tracts will also be used to tabulate and publish estimates from the American Community Survey (ACS) \2\ after 2010. The primary goal of the census tract program is to provide a set of nationally consistent small, statistical geographic units, with stable boundaries, that facilitate analysis of data across time.
Census Block Group Program for the 2010 Decennial Census-Final Criteria
Block groups are statistical geographic divisions of a census tract, defined for the tabulation and presentation of decennial census data. Block groups also will be used to tabulate and present period estimates from the American Community Survey (ACS) \1\ after 2010. Block groups provide the geographic framework within which the Bureau of the Census (Census Bureau) defines census blocks. Each block group comprises a reasonably compact and contiguous cluster of census blocks; up to nine block groups can be contained within a single census tract.