Results for the Early April 2003 Iraq survey are based on telephone interviews conducted under the direction of Princeton Survey Research Associates among a nationwide sample of 809 adults, 18 years of age or older, during the period April 8-9, 2003. 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 4 percentage points. For results based on April 8 (N=395) and April 9 (N=414) separately, the sampling error is plus or minus 5.5 percentage points.
Questions about parents and their children were asked on the March-April War Tracking survey during the period March 28 to April 7. Based on the subsample of 381 parents reported here, one can say with 95% confidence that the error attributable to sampling and other random effects is plus or minus 5.5 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.