The third part methodology of educational work with children this appendix introduces the projection methods and assumptions. The fourth section offers some important disclaimers about these projections.
World Religion Database and other sources. Censuses and nationally representative surveys can provide valid and reliable measures of religious landscapes when they are conducted following the best practices of social science research. Valid measurement in censuses and surveys also requires that respondents are free to provide information without fear of negative governmental or social consequences. The measure of religious identity in this study is sociological rather than theological.
In order to have statistics that are comparable across countries, the study attempts to count individuals who self-identify with each religion. This includes people who hold beliefs that may be viewed as unorthodox or heretical by others who claim the same religion. Standardization of Religious Categories and Measurement Strategies At least three researchers worked together to produce each country’s religious composition estimates, observing the general procedures and considerations described below. Pew Research Center staff standardized religion categories in all available censuses and surveys for each country. Censuses and surveys collect information on religious identity at different levels of specificity. For example, depending on the source, the most specific level of affiliation measured could be Christian, Protestant, Baptist or Southern Baptist.
Religious Composition Estimates After considering all evidence available, researchers identified one or more primary sources for each country’s religious composition estimate. In cases where censuses and surveys lacked sufficient detail on minority groups, the study also drew on estimates provided by the World Religion Database, which takes into account other sources of information on religious affiliation, including statistical reports from religious groups themselves. Adjusting for Limitations in a Survey Questionnaire Usually, researchers assumed that members of underrepresented groups were included in the sample but were not adequately measured by the survey instrument. Hindu when completing official forms such as the census. Adjusting for Sampling Limitations In some situations, underrepresented groups are likely to be omitted from the sample itself. For example, recent migrants who may not be fluent in the language used in a survey often are missing in samples.