RT Article T1 Falling Through the Cracks: Dealing with the Problem of the Unclassifieds in RELTRAD JF Review of religious research VO 63 IS 3 SP 411 OP 433 A1 Burge, Ryan P. A1 Djupe, Paul A. 1971- LA English PB Springer YR 2021 UL https://ixtheo.de/Record/177741864X AB RELTRAD is the most popular and widely used classification scheme for sorting religious traditions in the social sciences, however it struggles with how to sort non-denominational Protestants into one of the existing categories, with a growing number falling into an often ignored “unclassified” category. To demonstrate the growing problem of excluding non-denominational protestants who attend infrequently in the current iteration of RELTRAD. We assess the assumption that the “unclassified” respondents are akin to those who select a “don’t know” option and should be excluded. We also propose several ways to reintroduce low attending non-denominationals back into the larger sample. K1 Church Attendance K1 Measurement K1 Non-denominational K1 RELTRAD DO 10.1007/s13644-020-00441-y