Our surveys internationally are conducted via telephone or face-to-face interviews, depending on the country. The results are based on national samples, unless otherwise noted. Included here is detailed information, such as mode of interview, sampling design, margin of error, and design effect, for each country we survey, organized by country and by year.

For more general information on how we conduct our international survey research, visit here.

The margin of sampling error reported is based on all interviews conducted in a country. The margin of error takes into account the design effect due to clustering and weighting, where applicable. For results based on the full sample in a given country, one can say with 95% confidence that the error attributable to sampling and other random effects is plus or minus the margin of error. The margin of error is larger for results based on subsamples in the survey. Sample sizes and sampling errors for subgroups are available upon request. 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.


Survey Methods for Mexico in 2015

Country: Mexico
Year: 2015
Survey: Global Attitudes Spring 2015
Sample Design: Multi-stage, area probability design. Primary sampling units (PSUs) are electoral sections stratified by region, urbanity and the electoral majority party. The number of effective PSUs is 100. Individuals within households are selected using the next birthday method. At least three attempts are made to complete the interview with the selected respondent.
Mode: Face-to-face
Languages: Spanish
Fieldwork Dates: April 7 - 19, 2015
Sample Size: 1,000
Margin of Error: 4.1 percentage points
Representative: Adult population 18 plus (excluding one electoral section in Durango and Chiapas due to insecurity and one largely commercial municipality in the Federal District)
Primary Vendor: Princeton Survey Research Associates International
Weighting Variables: Gender, age and education within region and probablity of selection of PSU
Design Effects: 1.76