Results for this survey are based on telephone interviews conducted under the direction of Abt SRBI, Inc. among a nationwide sample of 1,502 adults, 18 years of age or older, from April 23-27, 2008. The following table shows the error attributable to sampling that would be expected at the 95% level of confidence for different groups in the survey:

In addition to sampling error, one should bear in mind that question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of opinion polls.

About the Center

The Pew Research Center for the People & the Press is an independent opinion research group that studies attitudes toward the press, politics and public policy issues. We are sponsored by The Pew Charitable Trusts and are one of eight projects that make up the Pew Research Center, a nonpartisan "fact tank" that provides information on the issues, attitudes and trends shaping America and the world.

The Center's purpose is to serve as a forum for ideas on the media and public policy through public opinion research. In this role it serves as an important information resource for political leaders, journalists, scholars, and public interest organizations. All of our current survey results are made available free of charge.

All of the Center's research and reports are collaborative products based on the input and analysis of the entire Center staff consisting of:

Andrew Kohut, Director
Scott Keeter, Director of Survey Research
Carroll Doherty and Michael Dimock, Associate Directors
Kim Parker, Senior Researcher
Juliana Menasce Horowitz, Robert Suls, Shawn Neidorf, Leah Christian and Jocelyn Kiley,
Research Associates
Kathleen Holzwart, Research Analyst
James Albrittain and Alec Tyson, Research Assistants