The 2010 Civic Health Index is based on The Center for Information & Research on Civic Learning and Engagement's (CIRCLE) analysis of Census Current Population Survey (CPS) data. Volunteering estimates are from CPS September Volunteering Supplement, 2007, 2008 and 2009, and data available from Volunteering in America. Voting and registration data come from the CPS November Voting/Registration Supplement, 2004 and 2008, and all other civic engagement indicators, such as access to information and connection to others, come from the 2008 and 2009 CPS Civic Engagement Supplement. For these indicators, the 2008 and 2009 data were combined whenever possible, to achieve the largest possible sample size and to minimize error.

For the Chicago Report, the sample size for citizen engagement was 3,929 and the sample size for volunteering 2,071.

Because we draw from multiple sources of data with varying sample sizes, we are not able to compute one margin of error for the state across all indicators. For Chicago, the sample size for major indicators varied from +/– 1.3% – 2.5%, depending on the sample size and other parameters associated with a specic indicator. Any analysis that breaks down the sample into smaller groups (gender, education) will have smaller samples and therefore the margin of error will increase. It is also important to emphasize that our margin of error estimates are approximate, as CPS sampling is highly complex and accurate estimation of error rates involves many parameters that are not publicly available.

The 2010 national report, America's Civic Health Assessment issue brief and executive summary can be found online at www.ncoc.net/CivicHealth2010. Rankings and data for all 50 states and 51 largest metropolitan areas are available at http://civic.serve.gov. The 2010 city report, Chicago Civic Health Index can be found online at www.ncoc.net/Chicago