The survey in Brazil is part of the larger 2010 Pew Global Attitudes survey conducted in 22 nations from April 7 to May 8, 2010, under the direction of Princeton Survey Research Associates International. (For more results from the 22-nation 2010 poll, see “Obama More Popular Abroad Than At Home, Global Image Of U.S. Continues To Benefit,” released June 17, 2010.)
Results for the survey in Brazil are based on 1,000 face-to-face interviews conducted April 10 to May 6, 2010. The survey’s multi-stage cluster sample design is representative of the country’s adult population. All interviews were conducted in Portuguese.
The margin of sampling error is ±4.5 percentage points. For the results based on the full sample, one can say with 95% confidence that the error attributable to sampling and other random effects is plus or minus the margin of error. 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.