U.S. Department of Justice Office of Justice Programs Bureau of Justice Statistics ******************************************************** This file is text only without graphics and many of the tables. A Zip archive of the tables in this report in spreadsheet format (.csv) and the full report including tables and graphics in .pdf format are available on BJS website at: http://bjs.gov/index.cfm?ty=pbdetail&iid=5366 This report is one in a series. More recent editions may be available. To view a list of all in the series go to http://bjs.gov/index.cfm?ty=pbse&sid=6 ********************************************************* Bulletin Criminal Victimization, 2014 Jennifer L. Truman, Ph.D., and Lynn Langton, Ph.D., BJS Statisticians In 2014, U.S. residents age 12 or older experienced an estimated 5.4 million violent victimizations and 15.3 million property victimizations, according to the Bureau of Justice Statistics’ (BJS) National Crime Victimization Survey (NCVS). There was no significant change in the overall rate of violent crime, defined as rape or sexual assault, robbery, aggravated assault, and simple assault, from 2013 (23.2 victimizations per 1,000 persons age 12 or older) to 2014 (20.1 per 1,000) (figure 1). However, the rate of violent crime in 2014 was lower than the rate in 2012 (26.1 per 1,000). From 1993 to 2014, the rate of violent crime declined from 79.8 to 20.1 per 1,000. The overall property crime rate (which includes household burglary, theft, and motor vehicle theft) decreased from 131.4 victimizations per 1,000 households in 2013 to 118.1 victimizations per 1,000 in 2014. The decline in theft accounted for the majority of the decrease in property crime. Since 1993, the rate of property crime declined from 351.8 to 118.1 victimizations per 1,000 households. *************************************************** ***************** HIGHLIGHTS ***************** Violent crime *************** * No significant change occurred in the rate of violent crime from 2013 (23.2 victimizations per 1,000) to 2014 (20.1 per 1,000). * From 2013 to 2014, no statistically significant change was detected in the rate of serious violence, domestic violence, intimate partner violence, violence resulting in an injury, and violence involving a firearm. * No significant change was found in the percentage of violent crime reported to police from 2013 to 2014 (46%). * About 12% of victims of serious violence and 28% of intimate partner violence victims received assistance from a victim service agency. * No change was observed in the percentage of violent crime victims who received assistance from a victim service agency from 2013 to 2014. Property crime *************** * The rate of property crime decreased from 131.4 victimizations per 1,000 households in 2013 to 118.1 per 1,000 in 2014. Prevalence of crime ********************* * In 2014, 1.1% of all persons age 12 or older (3 million persons) experienced at least one violent victimization. * An estimated 0.5% (1.2 million persons) experienced at least one serious violent victimization in 2014. * In 2014, 8% of all households (10.4 million households) experienced one or more property victimizations. * The prevalence rate of property victimization declined from 9% of all households in 2013 to 8% in 2014. *************************************************** ***************************************** No change was observed in the rate of serious violent crime from 2013 to 2014 ***************************************** There was no statistically significant change in the rate of serious violent crime—defined as rape or sexual assault, robbery, and aggravated assault—from 2013 (7.3 per 1,000) to 2014 (7.7 per 1,000) (table 1). The rate of simple assault declined from 15.8 victimizations per 1,000 persons in 2013 to 12.4 per 1,000 in 2014. Rates of total violent crime (down 29%) and simple assault (down 35%) were lower in 2014 than rates observed a decade earlier in 2005. *************************************************** The National Crime Victimization Survey (NCVS) The NCVS collects information on nonfatal crimes reported and not reported to police against persons age 12 or older from a nationally representative sample of U.S. households. Initial NCVS interviews are conducted in person with subsequent interviews conducted either in person or by phone. In 2014, the response rate was 84% for households and 87% for eligible persons. The NCVS produces national rates and levels of violent and property victimization, information on the characteristics of crimes and victims, and the consequences of victimization. Since NCVS is based on interviews with victims, it cannot measure homicide. The NCVS measures the violent crimes of rape or sexual assault, robbery, aggravated assault, and simple assault. The NCVS classifies rape, sexual assault, robbery, and aggravated assault as serious violent crimes. Property crimes include household burglary, motor vehicle theft, and theft. The survey also measures personal larceny, which includes pickpocketing and purse snatching. For additional estimates not included in this report, see the NCVS Victimization Analysis Tool (NVAT) on the BJS website. Victimization is the basic unit of analysis used throughout most of this report. A victimization is a crime as it affects one person or household. For personal crimes, the number of victimizations is equal to the number of victims present during a criminal incident. The number of victimizations may be greater than the number of incidents because more than one person may be victimized during an incident. Each crime against a household is counted as having a single victim—the affected household. The victimization rate is a measure of the occurrence of victimizations among a specified population group. For personal crimes, the victimization rate is based on the number of victimizations per 1,000 residents age 12 or older. For household crimes, the victimization rate is calculated using the number of incidents per 1,000 households. Estimates are presented for 2014, 2013, and 2005—the 10-year change. *************************************************** ***************************************** The rate of intimate partner violence remained stable from 2013 to 2014 ***************************************** The rate of domestic violence, which includes crime committed by intimate partners and family members, remained stable from 2013 to 2014 (4.2 per 1,000). No measurable change was detected from 2013 to 2014 in the rate of intimate partner violence (2.4 per 1,000), which includes victimizations committed by current or former spouses, boyfriends, or girlfriends. From 2013 to 2014, no statistically significant change was observed in the rate of violent victimizations committed by a stranger (8.1 per 1,000). However, the rate of violence committed by a stranger in 2014 was 30% lower than the rate 10 years earlier in 2005 (11.6 per 1,000). No statistically significant difference was found in rates of serious violent crime involving weapons (4.9 per 1,000) or resulting in physical injury to the victim (2.6 per 1,000) from 2013 to 2014. Like violent victimizations committed by a stranger, the rate of serious violent crime involving weapons in 2014 was 28% lower than the rate in 2005 (6.8 per 1,000). ***************************************** No change occurred in firearm violence from 2013 to 2014 ***************************************** No measurable change was detected in the rate of nonfatal firearm violence from 2013 (1.3 per 1,000) to 2014 (1.7 per 1,000) (table 2). An estimated 466,110 nonfatal firearm victimizations occurred in 2014, compared to 332,950 in 2013. The rate of firearm violence in 2014 was similar to the rate in 2005 (2.1 per 1,000). In 2014, about 82% of all serious violent crimes that involved a firearm were reported to police. No measurable change was detected in the percentage of firearm violence reported to police from 2013 to 2014. ***************************************** Property crime declined from 2013 to 2014 ***************************************** Following the decline from 2012 to 2013, the number and rate of property crime victimization decreased again from 2013 (131.4 victimizations per 1,000 households) to 2014 (118.1 per 1,000) (table 3). This recent decline was driven primarily by a decrease in theft. The rate of theft declined from 100.5 victimizations per 1,000 households in 2013 to 90.8 per 1,000 in 2014. The rate of household burglary decreased slightly, from 25.7 victimizations per 1,000 households in 2013 to 23.1 per 1,000 in 2014. During the same period, the rate of motor vehicle theft declined from 5.2 to 4.1 victimizations per 1,000. In 2014, rates of property crime, burglary, theft, and motor vehicle theft were lower than rates in 2005. *************************************************** ********************** Prevalence of crime ********************** Annual estimates of a population’s risk for criminal victimization can be examined using victimization rates or prevalence rates. Historically, Bureau of Justice Statistics (BJS) reports using National Crime Victimization Survey (NCVS) data have relied on victimization rates, which measure the extent to which victimizations occur in a specified population during a specific time. Victimization rates are used throughout this bulletin. For crimes affecting persons, NCVS victimization rates are estimated by dividing the number of victimizations that occur during a specified time (T) by the population at risk for those victimizations and multiplying the rate by 1,000. Victimization rate T = Number of victimizations experienced by a specified population T X 1000 Number of persons in the specified population T Prevalence rates also describe the level of victimization but are based on the number of unique persons (or households) in the population who experienced at least one victimization during a specified time. The key distinction between a victimization rate and a prevalence rate is whether the numerator consists of the number of victimizations or the number of victims. For example, a person who experienced two robberies on separate occasions within the past year would be counted twice in the victimization rate but counted once in the prevalence rate. Prevalence rates are estimated by dividing the number of victims in the specified population by the total number of persons in the population and multiplying the rate by 100. This is the percentage of the population victimized at least once in a given period. Prevalence rate T = Number of victims in a specified population T X 100 Number of persons in the specified population T Victimization and prevalence rates may also be produced for household crimes, such as burglary. In these instances, the numerators and denominators are adjusted to reflect households rather than persons. To better understand the percentage of the population that is victimized at least once in a given period, prevalence rates are presented by type of crime and certain demographic characteristics. (For more information about measuring prevalence in the NCVS, see Measuring the Prevalence of Crime with the National Crime Victimization Survey, NCJ 241656, BJS web, September 2013.) ***************************************** In 2014, 0.5% of all persons age 12 or older experienced serious violent crime ***************************************** In 2014, 1.1% of all persons age 12 or older (3 million persons) experienced at least one violent victimization (table 4). During the same period, 0.5% of all persons age 12 or older (1.2 million persons) experienced at least one serious violent victimization (rape or sexual assault, robbery, and aggravated assault). No measurable change occurred in the prevalence rate of total violent or serious violent victimization from 2013 to 2014. During the same period, the prevalence rates of simple assault declined slightly from about 0.8% to 0.7%. Less than 0.5% of all persons age 12 or older experienced one or more domestic violence (0.2%) or intimate partner violence (0.1%) victimizations in 2014. No measurable change occurred in the prevalence rates of domestic violence and intimate partner violence from 2013 to 2014. The prevalence of serious violence committed by strangers declined slightly from 2013 (0.19%) to 2014 (0.23%). In 2014, 8.0% of all households (10.4 million households) experienced one or more property victimizations. The prevalence rate of property victimization declined from 9.0% in 2013 to 8.0% in 2014. During the same period, the prevalence of household burglary, motor vehicle theft, and theft also declined. Similar to the property victimization rate, the decline in the prevalence rate of theft accounted for the majority of the decline in the prevalence rate of property victimization. ***************************************** Prevalence of violent crime among males and females remained stable from 2013 to 2014 ***************************************** In 2014, 1.2% of all males age 12 or older (1.5 million males) and 1.1% of all females (1.5 million females) experienced one or more violent victimizations (table 5). No measureable change occurred in the prevalence of violent crime for males or females from 2013 to 2014. Unlike in 2005 when a higher percentage of males than females were victims of one or more violent crimes, no significant difference was detected in the 2014 prevalence rates for males (1.2%) and females (1.1%) in 2014. No measurable change occurred in the prevalence rate for non- Hispanic whites or blacks from 2013 to 2014. While there were more than 3 times more white victims (1.8 million) than black victims (453,650) in 2014, blacks (1.4%) had higher prevalence rates than whites (1.1%). Unlike in 2013 when Hispanics had higher prevalence rates than whites, no significant difference was observed in Hispanic (1.1%) and white (1.1%) prevalence rates in 2014. This difference was because the prevalence of violent crime declined slightly for Hispanics from 2013 to 2014, but remained the same for whites. The prevalence of violent crime declined for persons ages 12 to 17 from 2013 (2.2%) to 2014 (1.7%). In 2013, persons ages 12 to 17 had the highest prevalence of violent crime of all age groups. In 2014, no significant difference was observed in the prevalence of violent crime among persons ages 12 to 17 (1.7%), ages 18 to 24 (1.6%), and ages 25 to 34 (1.5%). Persons age 65 or older (0.3%) had the lowest prevalence rate of violent crime. Persons who were never married had a higher prevalence rate of violent crime (1.6%) than persons who were married (0.6%) in 2014. Persons who were separated (3.0%) had the highest prevalence of violent crime in 2014. From 2013 to 2014, the prevalence of violent crime remained stable for persons of all marital statuses. *************************************************** ***************************************** In 2014, 46% of violent victimizations were reported to police ***************************************** The NCVS allows for examination of crimes reported and not reported to police. Victims may not report the victimization for a variety of reasons, including fear of reprisal or getting the offender in trouble, believing that police would not or could not do anything to help, and believing the crime to be a personal issue or too trivial to report. Police notification can come from the victim, a third party (including witnesses, other victims, household members, or other officials, such as school officials or workplace managers), or police being at the scene of the incident. Police notification may occur during or immediately following a criminal incident or at a later date. Police may include municipal police departments, sheriff’s offices, or other state or local law enforcement agencies. From 2013 to 2014, no statistically significant change was observed in the percentage of violent and serious violent victimizations reported to police (table 6). In 2014, 46% of violent victimizations and 56% of serious violent victimizations were reported to police. A greater percentage of robberies (61%) and aggravated assaults (58%) were reported to police than simple assaults (40%) and rape or sexual assaults (34%). In 2014, 37% of property victimizations were reported to police. From 2013 to 2014, no measurable change was detected in the percentage of total property victimizations, burglaries, or thefts reported to police. The percentage of reported motor vehicle thefts increased slightly from 75% to 83% during the same period. Similar to previous years, a larger percentage of motor vehicle thefts (83%) than burglaries (60%) and other thefts (29%) were reported to police in 2014. ***************************************** Rates of property crime reported and not reported to police declined from 2013 to 2014 ***************************************** From 2013 to 2014, no significant differences were detected in rates of any type of violent crime reported to police (table 7). With the exception of a slight decline in simple assault, rates of violent crime not reported to police also remained stable. In comparison, overall rates of property crime reported and not reported to police declined from 2013 to 2014. The overall rate of property crime reported to police decreased from 47.4 victimizations per 1,000 households in 2013 to 43.7 per 1,000 in 2014. This decline was driven largely by a slight decrease in thefts reported to police from 2013 (28.7 per 1,000) to 2014 (26.4 per 1,000). The rate of unreported property crime declined from 83.1 victimizations per 1,000 households in 2013 to 72.8 per 1,000 in 2014. The decline in unreported property crime occurred across all types of property crime measured by the NCVS. ***************************************** No change occurred in the percentage of violent crime victims who received assistance from a victim service agency over a 10-year span ***************************************** Victim service agencies are publicly or privately funded organizations that provide victims with support and services to aid their physical and emotional recovery, offer protection from future victimizations, guide them through the criminal justice system process, and assist them in obtaining restitution. From 2013 to 2014, no significant change was observed in the overall percentage of violent crime victims who received assistance from a victim service agency (10.5%) (table 8). In addition, no significant difference was detected in the percentage of violent crime victims who received assistance in 2014 compared to 10 years earlier in 2005. ***************************************** Violent crime decreased for Hispanics and young persons ***************************************** From 2013 to 2014, the rate of violent victimization for Hispanics declined 35% from 24.8 victimizations per 1,000 persons to 16.2 per 1,000 (table 9). With the decline, the violent victimization rate for Hispanics dropped below that for non- Hispanic blacks (22.5 per 1,000). This was a change from 2013, when blacks and Hispanics had similar rates of violent crime. No statistically significant difference was observed in rates of violent crime for non-Hispanic whites and Hispanics in 2013 and 2014. The decline in overall violent crime for Hispanics was largely driven by a decline in simple assault (not shown). The Hispanic rate of serious violent victimization remained relatively unchanged from 2013 (7.5 per 1,000) to 2014 (8.3 per 1,000). From 2013 to 2014, the violent victimization rate declined for persons ages 12 to 17, from 52.1 to 30.1 victimizations per 1,000. In 2013, persons ages 12 to 17 (52.1 per 1,000) had a higher rate of violent victimization than persons in any other age group. In 2014, no significant difference was observed in violent crime rates across persons ages 12 to 17, ages 18 to 24, or ages 25 to 34 (28.5 per 1,000). Like the decline in violence for Hispanics, the decline for persons ages 12 to 17 was largely driven by declines in simple assault (not shown). No significant difference was detected in the 2013 (10.8 per 1,000) and 2014 (8.8 per 1,000) rates of serious violence for persons ages 12 to 17. No other age groups had a measurable change in rates of violence or serious violence from 2013 to 2014. Rates of violent victimization were relatively unchanged from 2013 to 2014 for persons of all marital statuses, other than those who were never married. Violent victimization rates for persons who were never married decreased from 36.3 victimizations per 1,000 persons in 2013 to 27.9 per 1,000 in 2014. In 2014, persons who were separated had the highest rate of violent crime (52.8 per 1,000). Violent crime declined in the Northeast and the West ***************************************** From 2013 to 2014, rates of violent victimization decreased at least slightly in the Northeast and in the West, with no change detected in the South or Midwest (table 10). The rate of violent crime declined slightly in the West, from 27.3 to 20.3 victimizations per 1,000 persons. In the Northeast, the rate declined from 27.5 to 18.9 victimizations per 1,000 persons. No significant differences were observed in rates of violence or serious violence across any of the four regions in 2014. During the same period, there were also no significant differences in rates of violent crime across urban, suburban, and rural areas. Rates of serious violence were slightly higher in urban areas (9.3 per 1,000) in 2014 than in suburban (6.9 per 1,000) and rural (6.5 per 1,000) areas. From 2013 to 2014, property crime rates decreased in all regions of the country, except the Northeast where no significant change was detected in the rate. As in 2013, property crime rates were highest in the West (153.0 per 1,000) and lowest in the Northeast (85.8 per 1,000) in 2014. Property crime rates also declined in urban and suburban areas from 2013 to 2014, but did not change significantly in rural areas. Urban areas (148.8 per 1,000) had a higher rate of property crime victimization than suburban (101.7 per 1,000) and rural (103.2 per 1,000) areas. *************************************************** ***************************************** NCVS and UCR showed similar declines in property crime from 2013 to 2014 ***************************************** In the first half of 2014, preliminary findings from the FBI’s Uniform Crime Reporting (UCR) program showed a 5% decline in the number of serious violent crimes (table 11). The Bureau of Justice Statistics’ (BJS) National Crime Victimization Survey (NCVS) showed an apparent decline in serious violent victimizations which was not statistically significant. Because the NCVS and UCR measure an overlapping, but not identical, set of offenses and use different methodologies, congruity between the estimates is not expected. Throughout the 40-year history of the NCVS, both programs have generally demonstrated similar year-to-year increases or decreases in the levels of overall violent and property crimes. While this has not always been the case for certain crime types over the past 5 years, the two have generally shown similar declines in the two most recent reporting periods. The UCR measures the violent crimes of murder and nonnegligent manslaughter, forcible rape, robbery, and aggravated assault. For property crime, the UCR measures burglary, larceny-theft, and motor vehicle theft. The UCR measures crimes known to law enforcement, occurring against both persons and businesses. The FBI obtains data on crimes from law enforcement agencies, while the NCVS collects data through interviews with victims. Additional information about the differences between the two programs can be found in The Nation’s Two Crime Measures (NCJ 246832, BJS web, September 2014). Significant methodological and definitional differences exist between the NCVS and UCR: * The NCVS obtains estimates of crimes both reported and not reported to police, while the UCR collects data on crimes known to and recorded by law enforcement. * The UCR includes homicide and commercial crimes, while the NCVS excludes these crime types. * The UCR excludes simple assault and sexual assault, which are included in the NCVS.* * The NCVS estimates are based on data from a nationally representative sample of U.S. households. The UCR percentage changes are based on counts of offenses reported by a large sample of law enforcement agencies. *Simple assaults include attacks or attempted attacks without a weapon resulting in either no injury or minor injury. Sexual assaults include attacks or attempted attacks generally involving unwanted sexual contact between the victim and offender that may or may not involve force. * The NCVS excludes crimes against children age 11 or younger, persons in institutions (e.g., nursing homes and correctional institutions), and may exclude highly mobile populations and persons who are homeless. Victimizations against these persons are included in the UCR. Given these differences, the two measures of crime should complement each other and provide a more comprehensive picture of crime in the United States. In the first half of 2014, compared to the same period in 2013, the UCR showed declines in all types of serious violent and property crimes known to law enforcement. The number of NCVS motor vehicle thefts also declined 19% from 2013 to 2014, but the apparent decline in the NCVS estimate of overall serious violent crime was not statistically significant. While most of the NCVS estimates of crime reported to police did not change significantly from 2013 to 2014, the general direction of change in the NCVS estimates appeared to be consistent with the declines in UCR numbers. *************************************************** *************** Methodology *************** Survey coverage ***************** The National Crime Victimization Survey (NCVS) is an annual data collection conducted by the U.S. Census Bureau for the Bureau of Justice Statistics (BJS). The NCVS is a self-report survey in which interviewed persons are asked about the number and characteristics of victimizations experienced during the prior 6 months. The NCVS collects information on nonfatal personal crimes (rape or sexual assault, robbery, aggravated and simple assault, and personal larceny) and household property crimes (burglary, motor vehicle theft, and other theft) both reported and not reported to police. In addition to providing annual level and change estimates on criminal victimization, the NCVS is the primary source of information on the nature of criminal victimization incidents. Survey respondents provide information about themselves (e.g., age, sex, race and Hispanic origin, marital status, education level, and income) and whether they experienced a victimization. The NCVS collects information for each victimization incident about the offender (e.g., age, race and Hispanic origin, sex, and victim–offender relationship), characteristics of the crime (including time and place of occurrence, use of weapons, nature of injury, and economic consequences), whether the crime was reported to police, reasons the crime was or was not reported, and victim experiences with the criminal justice system. The NCVS is administered to persons age 12 or older from a nationally representative sample of households in the United States. The NCVS defines a household as a group of persons who all reside at a sampled address. Persons are considered household members when the sampled address is their usual place of residence at the time of the interview and when they have no usual place of residence elsewhere. Once selected, households remain in the sample for 3 years, and eligible persons in these households are interviewed every 6 months either in person or over the phone for a total of seven interviews. All first interviews are conducted in person with subsequent interviews conducted either in person or by phone. New households rotate into the sample on an ongoing basis to replace outgoing households that have been in the sample for the 3-year period. The sample includes persons living in group quarters, such as dormitories, rooming houses, and religious group dwellings, and excludes persons living in military barracks and institutional settings such as correctional or hospital facilities, and persons who are homeless. Nonresponse and weighting adjustments **************************************** In 2014, 90,380 households and 158,090 persons age 12 or older were interviewed for the NCVS. Each household was interviewed twice during the year. The response rate was 84% for households and 87% for eligible persons. Victimizations that occurred outside of the United States were excluded from this report. In 2014, less than 1% of the unweighted victimizations occurred outside of the United States and were excluded from the analyses. Estimates in this report use data from the 1993 to 2014 NCVS data files, weighted to produce annual estimates of victimization for persons age 12 or older living in U.S. households. Because the NCVS relies on a sample rather than a census of the entire U.S. population, weights are designed to inflate sample point estimates to known population totals and to compensate for survey nonresponse and other aspects of the sample design. The NCVS data files include both person and household weights. Person weights provide an estimate of the population represented by each person in the sample. Household weights provide an estimate of the U.S. household population represented by each household in the sample. After proper adjustment, both household and person weights are also typically used to form the denominator in calculations of crime rates. Victimization weights used in this analysis account for the number of persons present during an incident and for high- frequency repeat victimizations (i.e., series victimizations). Series victimizations are similar in type but occur with such frequency that a victim is unable to recall each individual event or describe each event in detail. Survey procedures allow NCVS interviewers to identify and classify these similar victimizations as series victimizations and to collect detailed information on only the most recent incident in the series. The weight counts series incidents as the actual number of incidents reported by the victim, up to a maximum of 10 incidents. Including series victimizations in national rates results in large increases in the level of violent victimization; however, trends in violent crime are generally similar, regardless of whether series victimizations are included. In 2014, series incidents accounted for about 1% of all victimizations and 4% of all violent victimizations. Weighting series incidents as the number of incidents up to a maximum of 10 incidents produces more reliable estimates of crime levels, while the cap at 10 minimizes the effect of extreme outliers on rates. Additional information on the series enumeration is detailed in the report Methods for Counting High-Frequency Repeat Victimizations in the National Crime Victimization Survey (NCJ 237308, BJS web, April 2012). Standard error computations ***************************** When national estimates are derived from a sample, as with the NCVS, caution must be used when comparing one estimate to another estimate or when comparing estimates over time. Although one estimate may be larger than another, estimates based on a sample have some degree of sampling error. The sampling error of an estimate depends on several factors, including the amount of variation in the responses and the size of the sample. When the sampling error around an estimate is taken into account, the estimates that appear different may not be statistically different. One measure of the sampling error associated with an estimate is the standard error. The standard error can vary from one estimate to the next. Generally, an estimate with a small standard error provides a more reliable approximation of the true value than an estimate with a large standard error. Estimates with relatively large standard errors are associated with less precision and reliability and should be interpreted with caution. To generate standard errors around numbers and estimates from the NCVS, the Census Bureau produced generalized variance function (GVF) parameters for BJS. The GVFs take into account aspects of the NCVS complex sample design and represent the curve fitted to a selection of individual standard errors based on the Jackknife Repeated Replication technique. The GVF parameters were used to generate standard errors for each point estimate (e.g., counts, percentages, and rates) in this report. BJS conducted tests to determine whether differences in estimated numbers, percentages, and rates in this report were statistically significant once sampling error was taken into account. Using statistical programs developed specifically for the NCVS, all comparisons in the text were tested for significance. The primary test procedure was the Student’s t-statistic, which tests the difference between two sample estimates. Differences described as higher, lower, or different passed a test at the 0.05 level of statistical significance (95% confidence level). Differences described as somewhat, slightly, or marginally different, or with some indication of difference, passed a test at the 0.10 level of statistical significance (90% confidence level). Caution is required when comparing estimates not explicitly discussed in this report. Data users can use the estimates and the standard errors of the estimates provided in this report to generate a confidence interval around the estimate as a measure of the margin of error. The following example illustrates how standard errors can be used to generate confidence intervals: According to the NCVS, in 2014, the violent victimization rate among persons age 12 or older was 20.1 per 1,000 persons (see table 1). Using the GVFs, it was determined that the estimated victimization rate has a standard error of 1.2 (see appendix table 2). A confidence interval around the estimate was generated by multiplying the standard errors by ±1.96 (the t-score of a normal, two-tailed distribution that excludes 2.5% at either end of the distribution). Therefore, the 95% confidence interval around the 20.1 estimate from 2014 is 20.1 ± (1.2 X 1.96) or (17.7 to 22.5). In others words, if different samples using the same procedures were taken from the U.S. population in 2014, 95% of the time the violent victimization rate would fall between 17.7 and 22.5 per 1,000 persons. In this report, BJS also calculated a coefficient of variation (CV) for all estimates, representing the ratio of the standard error to the estimate. CVs provide a measure of reliability and a means for comparing the precision of estimates across measures with differing levels or metrics. ***************************************** NCVS measurement of rape and sexual assault ***************************************** Definition of rape and sexual assault ************************************** 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 a variety of factors related to the interview process, including how items are worded, definitions are used, and the data collection mode. In addition, the legal definitions of rape and sexual assault vary across jurisdictions. For the NCVS, survey respondents are asked to respond to a series of questions about the nature and characteristics of their victimization. The NCVS classifies victimizations as rape or sexual assault even if other crimes, such as robbery or assault, occurred at the same time. Then, the NCVS uses the following rape and sexual assault definitions: Rape is the unlawful penetration of a person against the will of the victim, with use or threatened use of force, or attempting such an act. Rape includes psychological coercion and physical force, and forced sexual intercourse means vaginal, anal, or oral penetration by the offender. Rape also includes incidents where penetration is from a foreign object (e.g., a bottle), victimizations against male and female victims, and both heterosexual and homosexual rape. Attempted rape includes verbal threats of rape. Sexual assault is defined across a wide range of victimizations, separate from rape or attempted rape. These crimes include attacks or attempted attacks generally involving unwanted sexual contact between a victim and offender. Sexual assault may or may not involve force and includes grabbing or fondling. From 2005 to 2014, 30% of NCVS rape and sexual assault victimizations were classified as completed rape (table 12). Attempted rape or other sexual assault accounted for nearly 50% of rape or sexual assault victimizations. About 1 in 5 (18%) were verbal threats of rape or sexual assault. Comparison of NCVS estimates to other survey estimates ***************************************** Over the past several decades, a number of other surveys have also been used to study rape and sexual assault in the general population. BJS estimates of rape and sexual assault from the NCVS have typically been lower than estimates derived from other federal and private surveys. However, the NCVS methodology and definitions of rape and sexual assault differ from many of these surveys in important ways that contribute to the variation in estimates of the prevalence and incidence of these victimization. Additional information about differences in self-report estimates of rape and sexual assault is available on the BJS website. BJS continues an active research program on the collection of rape and sexual assault data in an effort to improve the quality and accuracy of these estimates. Despite the current differences in methods and estimates that exist between the NCVS and other surveys, a strength of the NCVS is its capacity to be used to make comparisons over time, as year-to-year comparisons are not affected by the NCVS methodology. Methodological differences that exist between the NCVS and the other surveys that lead to higher estimates of the levels of rape and sexual assault in the other surveys should not affect the within-NCVS comparisons of estimates from 2013 to 2014. ***************************************** Methodological changes to the NCVS in 2006 ***************************************** Methodological changes implemented in 2006 may have affected the crime estimates for that year to such an extent that they are not comparable to estimates from other years. Evaluation of 2007 and later data from the NCVS conducted by BJS and the Census Bureau found a high degree of confidence that estimates for 2007, 2008, 2009, 2010, 2011, 2012, 2013, and 2014 are consistent with and comparable to estimates for 2005 and previous years. The reports, Criminal Victimization, 2006 (NCJ 219413, December 2007); Criminal Victimization, 2007 (NCJ 224390, December 2008); Criminal Victimization, 2008 (NCJ 227777, September 2009); Criminal Victimization, 2009 (NCJ 231327, October 2010); Criminal Victimization, 2010 (NCJ 235508, September 2011); Criminal Victimization, 2011 (NCJ 239437, October 2012); Criminal Victimization, 2012 (NCJ 243389, October 2013); and Criminal Victimization, 2013 (NCJ 247648, September 2014) are available on the BJS website. ************************************************************* The Bureau of Justice Statistics of the U.S. Department of Justice is the principal federal agency responsible for measuring crime, criminal victimization, criminal offenders, victims of crime, correlates of crime, and the operation of criminal and civil justice systems at the federal, state, tribal, and local levels. BJS collects, analyzes, and disseminates reliable and valid statistics on crime and justice systems in the United States, supports improvements to state and local criminal justice information systems, and participates with national and international organizations to develop and recommend national standards for justice statistics. William J. Sabol is director. This report was written by Jennifer L. Truman and Lynn Langton. Erika Harrell verified the report. Jill Thomas and Morgan Young edited the report, and Barbara Quinn produced the report. August 2015, NCJ 248973 ************************************************************* ************************************************* Office of Justice Programs Innovation * Partnerships * Safer Neighborhoods www.ojp.usdoj.gov ************************************************* *************************** 8/10/2015 10:00am JER ***************************