American Community Survey (ACS)

This site has been updated to include national and state level quality measures for the 2007 and 2008 ACS 1-year estimates, joining the existing measures for the 2000 ACS through the 2006 ACS.

The Census Bureau will continue to provide both ACS 1-year and 3-year quality measures at the national, state, and, for selected measures, at the county level on American FactFinder in the B98 series of Detailed Tables.

The quality measures provided in this section illustrate the steps the Census Bureau takes to ensure that ACS survey data are accurate and reliable.

1. How large was the sample used to produce the ACS estimates? Sample Size: Select Nation/State United States All States 2008 All States 2007 All States 2006 All States 2005 All States 2004 All States 2003 All States 2002 All States 2001 All States 2000 Alabama Alaska Arizona Arkansas California Colorado Connecticut Delaware D.C. Florida Georgia Hawaii Idaho Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachusetts Michigan Minnesota Mississippi Missouri Montana Nebraska Nevada New Hampshire New Jersey New Mexico New York North Carolina North Dakota Ohio Oklahoma Oregon Pennsylvania Rhode Island South Carolina South Dakota Tennessee Texas Utah Vermont Virginia Washington West Virginia Wisconsin Wyoming Puerto Rico       Sample Size Definitions		3. What was the response to the survey? Response Rates: Select Nation/State United States All States 2008 All States 2007 All States 2006 All States 2005 All States 2004 All States 2003 All States 2002 All States 2001 All States 2000 Alabama Alaska Arizona Arkansas California Colorado Connecticut Delaware D.C. Florida Georgia Hawaii Idaho Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachusetts Michigan Minnesota Mississippi Missouri Montana Nebraska Nevada New Hampshire New Jersey New Mexico New York North Carolina North Dakota Ohio Oklahoma Oregon Pennsylvania Rhode Island South Carolina South Dakota Tennessee Texas Utah Vermont Virginia Washington West Virginia Wisconsin Wyoming Puerto Rico       Response Rates Definitions
2. How well does the ACS cover the population? Coverage Rates: Select Nation/State United States All States 2008 All States 2007 All States 2006 All States 2005 All States 2004 All States 2003 All States 2002 All States 2001 All States 2000 Alabama Alaska Arizona Arkansas California Colorado Connecticut Delaware D.C. Florida Georgia Hawaii Idaho Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachusetts Michigan Minnesota Mississippi Missouri Montana Nebraska Nevada New Hampshire New Jersey New Mexico New York North Carolina North Dakota Ohio Oklahoma Oregon Pennsylvania Rhode Island South Carolina South Dakota Tennessee Texas Utah Vermont Virginia Washington West Virginia Wisconsin Wyoming Puerto Rico       Coverage Rates Definitions		4. How complete were the data used to produce a specific estimate? Item Allocation Rates: Select Nation/State United States Alabama Alaska Arizona Arkansas California Colorado Connecticut Delaware D.C. Florida Georgia Hawaii Idaho Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachusetts Michigan Minnesota Mississippi Missouri Montana Nebraska Nevada New Hampshire New Jersey New Mexico New York North Carolina North Dakota Ohio Oklahoma Oregon Pennsylvania Rhode Island South Carolina South Dakota Tennessee Texas Utah Vermont Virginia Washington West Virginia Wisconsin Wyoming Puerto Rico       Item Allocation Rates Definitions

The ACS produces survey data each year to measure key social, economic, and housing characteristics about the U.S. population. The four questions above identify four important aspects of survey quality. These quality measures are produced annually to accompany each ACS data release and describe the quality of those data. The quality measures are available at national and state levels. Clicking on "definitions" will provide additional information on each of these measures, including why the measure is important and how it was calculated.

Data for Puerto Rico are available starting with 2005. You can access the Puerto Rico data in two different ways. If you select the 'All States' view off the 'Select Nation/State' pick list, Puerto Rico data are shown at the bottom of the view. You can also select Puerto Rico directly at the bottom of the 'Select Nation/State' pick list. The numbers and rates for the United States do not include Puerto Rico.