Appendix C: Survey Methodology
Results for the survey are based on face-to-face interviews conducted under the direction of Princeton Survey Research Associates International. The survey is based on national samples except in Chad and the Democratic Republic of the Congo, where the samples were disproportionately urban. Muslim oversamples were conducted in Ghana, Kenya and Uganda, in addition to a national sample. Oversampling was done via disproportionate sampling in certain locations rather
than by screening for religion. The Muslim samples in Cameroon, the Democratic Republic of the Congo, Ethiopia, Ghana, Kenya, Liberia and Mozambique are disproportionately male (56% or more). Analysis of the survey reveals that the large share of males among Muslims in these countries makes little substantive difference for the survey findings.
A table shows the sample size and margin of sampling error for three groups (total population, Christians and Muslims) in each country. 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. 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. The table is followed by additional methodological details for each country.
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Part of the Pew-Templeton Global Religious Futures Project