Results for this report are based on two separate telephone surveys conducted under the direction of Princeton Survey Research Associates International. The first survey is among a nationwide sample of 1,502 adults, 18 years of age or older, from July 13-17, 2005. For results based on the total sample, one can say with 95% confidence that the error attributable to sampling is plus or minus 3 percentage points. For results based on Form 1 (N=751) or Form 2 (N=751) only, the error attributable to sampling is plus or minus 4 percentage points.
Results for second survey are based on telephone interviews among a nationwide sample 2,000 adults, 18 years of age or older, from July 7-17, 2005. For results based on the total sample, one can say with 95% confidence that the error attributable to sampling is plus or minus 2.5 percentage points. For results based on Form 1 (N=1,000) or Form 2 (N=1,000) only, the error attributable to sampling is plus or minus 3.5 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.
