["Journal for the Scientific Study of Religion, Volume 61, Issue 1, Page 242-257, March 2022. ", "\nAbstract\nThe term “Protestant” is used extensively by scholars of religion and has been included in surveys about American religion for decades. Yet it is possible that many Americans do not have a full understanding of the meaning of this term and its inclusion may be introducing measurement error on surveys. Two recent survey efforts provide illumination to this question. The Nationscape question on religion replicates all the options included in the Cooperative Survey, but also includes an option for “Christian.” This provides an ideal opportunity to assess the implications of adding this response choice. When the “Protestant” and “Christian” groups are combined in the Nationscape and compared to the “Protestant” group in the Cooperative Election Study (CES), there is a great deal of similarity between the two samples. But, the results from the Nationscape indicate that the term “Protestant” is becoming increasingly unfamiliar to younger Americans, especially for racial minorities.\n"]