Dane gospodarcze · 1/9/1998

Block Group Program for Census 2000Final Criteria

Block groups are geographic statistical divisions of census tracts, each of which consists of from one to nine block groups. A block group comprises a reasonably compact and contiguous cluster of census blocks. The primary goal of the block group program is to provide data users with a geographic subunit of census tracts for which decennial census sample and 100 percent data are tabulated and disseminated. The Census Bureau first used block groups in its data presentations from the 1970 census. It did this in lieu of providing data summaries for enumeration districts in areas that had census block numbers. As census blocks and block groups became increasingly popular with data users, the Census Bureau established them in many new areas. By 1990, there was complete census block and block group coverage for all of the United States, Puerto Rico, and the Island Areas (American Samoa, Guam, the Northern Mariana Islands, and the Virgin Islands of the United States). Through the 1990 census, block groups were subunits either of census tracts or of statistically equivalent entities known as block numbering areas (BNAs). For areas where census tracts did not exist, the Census Bureau had es