This report is based on results of two February surveys conducted by the Pew Research Center. Portions of the analysis are based on the combined samples of the two surveys, with a total 1,898 registered voters. Based on this combined sample, one can say with 95% confidence that the error attributable to sampling and other random effects is plus or minus 2.5 percentage points.
Results for the February 2004 News Interest Index survey are based on telephone interviews conducted under the direction of Princeton Survey Research Associates among a nationwide sample of 1,500 adults, 18 years of age or older, during the period February 11-16, 2004. Based on the total sample, one can say with 95% confidence that the error attributable to sampling and other random effects is plus or minus 3 percentage points. For results based on Registered Voters (N=1149), the sampling error is plus or minus 3.5 percentage points.
Results for the February 2004 Global Attitudes Project — US Survey are based on telephone interviews conducted under the direction of Princeton Survey Research Associates among a nationwide sample of 1,000 adults, 18 years of age or older, during the period February 24-29, 2004. Based on the total sample, one can say with 95% confidence that the error attributable to sampling and other random effects is plus or minus 3.5 percentage points. For results based on Registered Voters (N=749), the sampling error is plus or minus 4 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.