There are two national crime series which have data on crime rates and trends. The National Crime Victimization Survey (NCVS) is based upon a sample of households and includes both crimes that are reported to police and those that are not reported. The Uniform Crime Reports (UCR) is based upon local police reports which are compiled by the FBI. See (link) for a more detailed explanation of each data set. The two data series complement each other and both are “right” in terms of measuring what they are designed to measure. Please see the report, The Nation’s Two Crime Measures (NCJ 246832, BJS web), for more information.
Number of victimizations per 1,000 persons or households in a given population that occurred during the year.
NIBRS stands for National Incident-Based Reporting System. Unlike the FBI's Uniform Crime Reporting (UCR) Program, which only collects data on the most serious offense that occurs during a criminal incident, NIBRS collects data on each reported offense occurring during criminal incident. You can learn more about NIBRS in the NIBRS Edition of the FBI's CJIS newsletter.
Though the NCVS was originally designed to provide national level estimates of criminal victimization, BJS has recognized an increasing need for victimization data at the state and local level. BJS has developed multiple approaches for obtaining subnational NCVS estimates, see NCVS Redesign: Subnational for additional information about these approaches.
UCR stands for the Uniform Crime Reporting Program, a project of the FBI. You can learn more about the UCR program on the FBI website.
The NCVS and UCR both offer important information on criminal victimization; however, the two programs were created to serve different purposes. The primary objective of the UCR is to provide a reliable set of criminal justice statistics for law enforcement administration, operation, and management. The NCVS was established to provide previously unavailable information about crime (including crime not reported to police), victims, and offenders. More information on the similarities and differences between the NCVS and UCR can be found in Nation's Two Crime Measures
The NCVS is designed to measure crime on a yearly basis. Criminologists have many theories about what causes crime rates to go up or down. There is no consensus among criminologists or others about the causes of crime or changes in crime rates. You may wish to read some of the literature in the criminology field to obtain more information about differing ideas on this topic.
The NCVS measures violent and property crime experienced by victims in the United States. This includes—
- Violent crimes of rape or sexual assault, robbery, aggravated or simple assault.
- Personal theft.
- Property crimes of household burglary, motor vehicle theft, and theft.
- Routine supplements address: identity theft, stalking, and contacts between the police and the public.
No, kidnapping is not a crime that is covered by the NCVS.
The measurement of rape and sexual assault presents many challenges. Victims may not be willing to reveal or share their experiences with an interviewer. The level and type of sexual violence reported by victims is sensitive to a variety of factors related to the interview process, including how items are worded, what definitions are used, and the data collection mode. In addition, the legal definitions of rape and sexual assault vary across jurisdictions. While the change in the rape or sexual assault rate from year to year may be significantly different, care should be taken in interpreting this change because the estimates of rape or sexual assault are based on a small number of cases reported to the survey. Therefore, small absolute changes and fluctuations in the rates of victimization can result in larger year-to-year change estimates. BJS has initiated projects to identify, develop, and test the best methods for collecting self-report data on rape and sexual assault. For more information on BJS's active research program on the collection of rape and sexual assault data, see Measuring Rape and Sexual Assault.