Census 2000 SF3 Frequently Asked Questions Tuesday, December 23, 2003
What is a Census 2000 SF3? Summary File 3 (SF3) consists of 813 detailed tables of Census 2000 social, economic and housing characteristics compiled from a sample of approximately 19 million housing units (about 1 in 6 households) that received the Census 2000 long-form questionnaire. Fifty-one tables are repeated for nine major race and Hispanic or Latino groups: White alone; Black or African American alone; American Indian and Alaska Native alone; Asian alone; Native Hawaiian and Other Pacific Islander alone; Some other race alone; Two or more races; Hispanic or Latino; and White alone, not Hispanic or Latino.

What data formats are available?

The Atlas Census 2000 SF3 downloader currently offers two formats for downloading SF3 data: comma separate values (csv) and ESRI shapefile (shp). To view a web page with more information about these two formats, click here.
What programs can I use to view the SF3 files? A number of different programs can read the csv and shp formats. MicroSoft Excel and Access can easily read the csv format. Most GIS applications can do so also. Most GIS applications such as Intergraph Geomedia and ESRI ArcView can read the shp format and create thematic maps.
Where can I get more information about SF3 data?

For more information, see the "U.S. Census Bureau, 2000 Census of Population and Housing, Summary File 3: Technical Documentation, 2002" document which can be downloaded from Atlas at http://atlas.lsu.edu/census2000sf3/sf3.pdf. For more information about Census SF3 data, visit the U.S. Census Bureau's website at http://www.census.gov/Press-Release/www/2002/sumfile3.html.

How can view the SF3 data online? The parish data of SF3 can be viewed through the Atlas Demographics Page at http://atlas.lsu.edu/demographics.
What summary levels can I download from Atlas? The geography summary levels available through the Atlas Census 2000 SF3 downloader are block groups (for the tables P### and H###), tracts, parishes, congressional districts for the 106th Congress, and zip code tabulations areas for 3 digit and 5 digit zip codes. To view a web page with more information abou the geography summary levels, click here.
What is the difference between SF3 data and data from SF1 and SF2? SF3 data uses data from the Census 2000 long form whereas SF1 and SF2 uses short form data. Since not every household received a long form, as in earlier censuses, the responses from the sample of households reporting on long forms must be weighted to reflect the entire population. Specifically, each responding household represents, on average, six or seven other households who reported using short forms.

For information regarding comparing SF3 and SF1 data, visit
Why does Atlas need to "assemble" some datasets? There are 813 tables that can be downloaded by at least five different geography summary levels in two different formats making 8,130 different Winzip archives needed to download the SF3. Instead of creating all 8,130 archives at once, Atlas creates them as needed. The first time that an Atlas requests a particular table-geography-format combination, Atlas creates the Winzip archive and downloads it for the user. Atlas also stores the Winzip archive for reuse when a later user requests the same table-geography-format combination.