This report outlines the development, methodology, and results of the split-half administration of the 2015 School Crime Supplement (SCS) to the National Crime Victimization Survey (NCVS). The National Crime Victimization Survey (NCVS) is sponsored by the U.S. Department of Justice, Bureau of Justice Statistics (BJS). The National Center for Education Statistics (NCES) collaborated with BJS to design the SCS as a supplement to the NCVS. Census conducted the SCS along with the NCVS in 1989, 1995, 1999, and every two years from 1999 to the present. The survey is administered to youth ages 12-18 in participating NCVS households who were enrolled in any of the grades 6-12 and attended public or private school for at least part of the school year concurrent with the survey year. The 2015 SCS was administered between January and June of 2015. The results of these analyses indicated that the bullying estimates derived from the new 2015 SCS bullying items were not similar to estimates derived from the historic bullying items alone. However, it also was determined that the two new bullying estimates (version 1 + RP, and version 2) were not similar to each other, although both were designed to make explicit to students the same elements--repetition and power imbalance--of the uniform bullying definition. Further analysis is planned to help determine what constructs are being measured by the two new versions of the bullying questions. For the 2015 SCS, NCES recommends use of only the data collected from the historic questions presented in version 1 to derive national estimates of reported bullying victimization in school among 12 to 18 year olds. This will allow for continuity with previous NCES data and prevent the dissemination of conflicting estimates of bullying victimization from the 2015 data. The following are appended: (1) School Crime Supplement to the National Crime Victimization Survey Details of Survey Question Changes From 2013 to 2015; and (2) 2015 School Crime Supplement Questionnaire.