The U.S. Census Bureau continuously makes improvements to the American Community Survey (ACS) in an ongoing effort to best meet the needs of its data users. In 2008, this included several changes designed to improve the content and data quality of the ACS and provide new tools and resources for data users.

The Census Bureau worked closely with the Interagency Committee for the ACS to update the content of the ACS questionnaire by adding required new content and improving the accuracy and reliability of existing questions. The proposed changes went through cognitive testing followed by field testing in the 2006 ACS Content Test. As a consequence of this testing, the 2008 ACS included new questions on marital history, health insurance coverage, and service-connected disability status and ratings and modifications to several existing questions, including major changes to the disability questions. An overview of the changes that were made to the questionnaire and the impact on the estimates that were observed in the 2006 ACS Content Test is available in the New and Modified Content on the 2008 ACS Questionnaire: Results of Testing Prior to Implementation. A comprehensive report for each item tested on the 2006 ACS Content Test is also available. To view, see 2006 Content Test Report Series.

Similar to last year, there are approximately 260 changes in the 2008 ACS 1-year data products on a base of roughly 1,600 tables. This includes the addition of roughly 100 new tables, the modification of roughly 50 existing tables, and the removal of roughly 100 existing tables. Most of these changes are in response to improvements to the 2008 ACS questionnaire and changes to tabulated categories for select topics.

For more information on the changes to the 2008 data products, see 2008 Data Product Changes.

The Census Bureau is introducing a series of briefs spotlighting the economic characteristics of the nation, states, District of Columbia, and Puerto Rico using data from the 2008 ACS 1-year estimates. The briefs cover the following topics:

The Census Bureau has updated the Quality Measures section of the ACS website to include national and state level quality measures for the 2007 and 2008 1-year estimates, joining the existing quality measures for the 2000 ACS through the 2006 ACS. The quality measures include sample sizes, coverage rates, response rates, and item allocation rates. We will continue to provide both 1-year and 3-year quality measures at the national, state, and, for selected measures, county level on American FactFinder in the B98 series of Detailed Tables.

The "+/-" sign in the Margin of Error (MOE) column of all ACS data products will be removed, including those for previous years. The MOE column header will read "Margin of Error (+/-)." This will allow users who download tables from AFF the opportunity to easily perform calculations. This feature is only available in the downloaded files and will not change the table presentation when viewed in AFF.

Educational materials are available to help users better understand and appropriately use ACS data. These materials include user-specific handbooks, fully scripted PowerPoint presentations, and an e-learning tutorial. Each handbook is designed to instruct and provide guidance to a particular audience. Currently, there are 11 handbooks available for download. The PowerPoint Presentations cover various ACS topics and are designed to promote self-learning. A web-based tutorial is planned for release in 2010 and will provide user-friendly training on the ACS, including "how to" demonstrations of accessing ACS data products in American FactFinder. To access these educational materials, see The ACS Compass Products: