Interviewing for the survey was conducted by telephone March 8-28, 2006 among a sample of 1,503 adults age 18 and older. Of these, 1,286 were cell phone users. Approximately half of the interviews (752) were conducted using a landline number frame, with the remainder conducted from a cell phone number frame (751). Both sampling frames were designed by Survey Sampling, Inc. In order to compensate respondents for any toll charges incurred, those interviewed from the cell phone frame were offered an incentive of $10 for completing the survey. Interviewing was conducted by the research firm Schulman, Ronca & Bucuvalas, Inc (SRBI). The samples were prepared by Survey Sampling, Inc.

The data were weighted using demographic weighting parameters derived from the March 2005 Census Bureau's Current Population Survey, along with estimates of current patterns of telephone status in the U.S., using an iterative technique that simultaneously balances the distributions of all weighting parameters.

Sampling errors for the survey are reported in the sample size table on the next page. 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 six 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
Jodie Allen, Senior Editor
Scott Keeter, Director of Survey Research
Carroll Doherty and Michael Dimock, Associate Directors
Carolyn Funk and Richard Wike, Senior Project Directors
Nilanthi Samaranayake, Peyton Craighill, Courtney Kennedy, April Rapp, Juliana Menasce Horowitz, Research Associates
Rob Suls, Research Analyst
Kate DeLuca, Research Assistant