About the General Public Survey
Results for the general public survey are based on telephone interviews conducted under the direction of Abt SRBI Inc. among a national sample of 2,000 adults living in the continental United States, 18 years of age or older, from October 28-November 8, 2009 (1500 respondents were interviewed on a landline telephone, and 500 were interviewed on a cell phone, including 193 who had no landline telephone). Both the landline and cell phone samples were provided by Survey Sampling International. Interviews were conducted in English and Spanish.
The combined landline and cell phone sample are weighted using an iterative technique that matches gender, age, education, race/ethnicity, region, and population density to parameters from the March 2008 Census Bureau’s Current Population Survey. The sample also is weighted to match current patterns of telephone status and relative usage of landline and cell phones (for those with both), based on extrapolations from the 2008 National Health Interview Survey. The weighting procedure also accounts for the fact that respondents with both landline and cell phones have a greater probability of being included in the combined sample and adjusts for household size within the landline sample. Sampling errors and statistical tests of significance take into account the effect of weighting. For detailed information about our survey methodology, see https://legacy.pewresearch.org/politics/methodology/.
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 Survey of Foreign Policy Opinion Leaders
Results for the survey of foreign policy opinion leaders are based on 642 web and telephone interviews conducted from October 2 to November 16, 2009 with members of the Council on Foreign Relations (CFR), under the direction of Princeton Survey Research Associates International, a sample of 1,000 members was drawn randomly from the CFR membership list; a total of 642 of the 1,000 sampled members completed the interview, with 506 completing the survey online and 136 by phone. The overall response rate for the survey is 64%.
Founded in 1921, the Council on Foreign Relations is an independent, nonpartisan membership organization, think tank and publisher dedicated to helping its members, government officials, journalists and others better understand the world and foreign policy. CFR publishes Foreign Affairs, a journal of international affairs and U.S. foreign policy. Individual membership is limited to U.S. citizens and U.S. residents in the process of becoming citizens. New members must be nominated by a current member. For more information about CFR, see http://www.cfr.org.
Each member sampled was mailed a letter describing the nature and purpose of the survey and encouraging participation in the survey. This letter contained a URL and a password for a secure web site where the survey could be completed. It also included a toll-free number for respondents to call if they had questions or if they preferred to take the survey by telephone. CFR members who did not participate in the first week after the mailing were sent follow up e-mails and/or received telephone calls to encourage them to participate in the survey.
In estimating the overall balance of opinion among Council on Foreign Relations members based on the total sample of 642 interviews completed, the margin of error attributable to sampling is plus or minus 4.5 percentage points. 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.
Additional Data Sources:
In addition to the main surveys described above, this report is supplemented with public opinion data from three other survey projects.
November 12-15 Omnibus:
Conducted under the direction of Princeton Survey Research Associates International among a national sample of 1,003 adults living in the continental United States, 18 years of age or older, from November 12-15 (700 respondents were interviewed on a landline telephone, and 303 were interviewed on a cell phone, including 92 who had no landline telephone.) Both the landline and cell phone samples were provided by Survey Sampling International. Interviews were conducted in English. The error attributable to sampling that would be expected at the 95% level of confidence for the total sample is plus or minus 4 percentage points. Sampling errors and statistical tests of significance take into account the effect of weighting.
May 27-June 10 and September 10-15 Global Attitudes Surveys:
Favorability ratings of various countries discussed in this report are from two Pew Global Attitudes Project surveys. Both surveys were conducted by telephone by Princeton Survey Research Associates International with national samples of adults living in the continental United States, 18 years of age or older. Interviews were conducted in English.
The first survey was conducted May 27-June 10, 2009 among 1,000 people (750 respondents were interviewed on a landline telephone and 250 were interviewed on a cell phone, including 97 who had no landline telephone.) The error attributable to sampling that would be expected at the 95% level of confidence for the total sample is plus or minus 4 percentage points. The second survey was conducted September 10-15, 2009 among 1,006 people (754 respondents were interviewed on a landline and 252 were interviewed on a cell phone, including 103 who had no landline telephone.) The error attributable to sampling that would be expected at the 95% level of confidence for the total sample is plus or minus 4 percentage points. The landline and cell phone samples for both surveys were provided by Survey Sampling International. Sampling errors and statistical tests of significance take into account the effect of weighting.
