Examines the nature and extent of series victimization in the National Crime Victimization Survey (NCVS). This technical report assesses the general patterns of victims' responses to being asked, "How many times did this type of incident occur?" and provides data on how reports of high-frequency repeat victimizations have changed over time. It describes how different procedures for counting series victimizations would affect estimates of the level and annual rate of change in victimization for various crime types and incident characteristics. The report also describes how Bureau of Justice Statistics (BJS) will change its counting practices for estimating annual victimization rates in future reports. An appendix contains 15 tables.