Survey Methods 2015

The Faith Communities Today 2015 national data set brings together the 11 individual surveys of congregations in addition to a random national survey of non-partner congregations.  The Cooperative Congregations Studies Partnership (CCSP) developed a common core questionnaire of between 150 and 200 questions consisting of items from the previous surveys as well as select modules of themed questions.  
Using the common questionnaire, CCSP partners conducted their own, typically by mail or online, surveys of a representative, random national sample of their own congregations. Usually a congregation's leader completed the questionnaire.  Finally, CCSP contracted with a denominational agency to survey a sample of non-partner denomination congregations.  This survey was based on a random sample drawn from a database of congregations maintained and kindly provided for free by FaithStreet.
For purposes of the overall national analysis, the various sub surveys were combined in such a way that, through the use of statistical weights, each partner denomination and faith group and each non-partner cluster of congregations is represented in the national FACT2015 data proportionate to its representation in the total population of congregations in the United States.  This aggregated data set includes responses from 4,436 congregations.    Sampling error for a survey such as this can only be roughly estimated.  We believe a conservative estimate is +/- 4% at the 95% confidence level.
Further information about the 2015 survey can be found on the final page of the Summary Report.