Date:    Nov. 19, 2013




National Crime Victimization Survey Is Likely Undercounting Rape and Sexual Assault; Justice Department Should Create New, Separate Survey


WASHINGTON – One of the nation’s largest surveys of crime victims is likely undercounting incidences of rape and sexual assault, making it difficult to ensure that adequate law enforcement resources and support services are available for victims, says a new report by the National Research Council.  To obtain more accurate data, the U.S. Department of Justice’s Bureau of Justice Statistics (BJS) should establish a separate survey for measuring rape and sexual assault.


“Victims of rape and sexual assault sustain devastating injuries, which often extend beyond the initial incident and potentially lead to health- and work-related issues,” said Candace Kruttschnitt, co-chair of the panel that wrote the report and professor of sociology at the University of Toronto.  “Understanding the context and frequency with which these crimes occur is essential for informed public health policymaking, providing support to victims, and helping to curtail future attacks.”


"To more accurately measure when and how these victimizations occur, we recommend a separate survey that is focused on these specific crimes within a public health context and targets those most at risk for sexual violence,” added William Kalsbeek, who also co-chaired the panel and is a professor of biostatistics at the University of North Carolina.


The National Crime Victimization Survey (NCVS) is conducted on an ongoing basis to obtain information on a broad set of crimes from the victims rather than the police. It is conducted for BJS by the U.S. Census Bureau, which selects households to survey through the same infrastructure built for the decennial census.  Each household address remains in the sample for three years, with interviews every six months. 


The NCVS is widely considered the best source of information for many kinds of criminal victimizations. However, the survey presents unique challenges for measuring low-frequency incidents, such as rape and sexual assault, which accounted for 1 percent or 217,331 of the criminal victimizations identified through the NCVS in 2011.  Over the years, several other surveys, including the National Women’s Study, the National College Women Sexual Victimization Study, and the National Intimate Partner and Sexual Violence Study, have measured higher rates of rape and sexual assault than the NCVS.  Even though these surveys have substantial differences -- the populations they target, their definitions of rape, and their data collection methodologies and timing -- the panel concluded that the NCVS was likely undercounting incidences of rape and sexual assault because of how the omnibus survey is designed and administered.


The report says lack of privacy may be a major reason for underreporting rape and sexual assault in the NCVS, which relies on oral interviews conducted within a household by an interviewer. Because most rapes and sexual assaults are committed by individuals whom the victim knows, respondents may be reluctant to disclose their victimization during an interview that takes place in the home within earshot of other family members.  The training for NCVS interviewers does not stress privacy, and even if adequate training were provided, the nature of the survey -- a general-purpose criminal victimization survey -- means that interviewers very rarely get positive responses on questions of rape and sexual assault.


The new survey recommended by the panel should be administered in a neutral context, such as a survey of health and well-being, instead of within the criminal context of the current NCVS.  Framing questions about rape and sexual assault within the confines of crime can limit responses.  For example, a respondent may believe that because the police weren’t contacted about an incident, it should not be reported on a government crime survey.  A victim may also understand that an act was criminal but not want to report it on the survey for fear of reprisal.  The new survey should continue to measure rape and sexual assault as “point-in-time” events with sufficient detail about the events so that they can later be coded as criminal events or not.


Survey questions should be worded to describe specific actions rather than the more ambiguous term “rape,” which is not defined uniformly by the FBI, states, or jurisdictions.  Survey respondents may interpret the word differently and not realize that what they experienced (for example, being forced by a companion to have sex while being too intoxicated to resist) might fit the definition of rape.  By responding to questions that simply ask whether specific actions have occurred, victims may be better able to express their victimizations without interpreting whether those incidents should be defined as rape or sexual assault.


The new survey should also focus more attention on “at risk” subpopulations that have a higher likelihood of being victims of rape and sexual assault.  This approach can improve the overall precision of the estimates, both at the national level and for important demographic subpopulations defined by age, race, and socio-economic variations.  More precise estimates would allow for more informed policymaking and better allocation of resources to prevent crime and support victims, the report says.


The study was sponsored by the Bureau of Justice Statistics of the U.S. Department of Justice. The National Research Council is the principal operating arm of the National Academy of Sciences and the National Academy of Engineering. Together with the Institute of Medicine, these private, nonprofit institutions provide science, technology, and health policy advice under a congressional charter granted to NAS in 1863.  For more information, visit  A panel roster follows.



Rachel Brody, Media Relations Associate

Office of News and Public Information

202-334-2138; e-mail

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Additional Resources:

Full Report
Report in brief


Pre-publication copies of Estimating the Incidence of Rape and Sexual Assault are available from the National Academies Press at or by calling tel. 202-334-3313 or 1-800-624-6242.  Reporters may obtain a copy from the Office of News and Public Information (contacts listed above).


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Division of Behavioral and Social Sciences and Education

Committee on National Statistics


Panel on Measuring Rape and Sexual Assault in Bureau of Justice Statistics Household Surveys


Candace Kruttschnitt (co-chair)


Department of Sociology

University of Toronto



William D. Kalsbeek (co-chair)

Professor of Biostatistics, and

Former Director

Survey Research Unit

Department of Biostatistics

University of North Carolina

Chapel Hill


Paul P. Biemer

Distinguished Fellow in Statistics

RTI International, and

Associate Director for Survey Research

Odum Institute for Research in Social Sciences

University of North Carolina

Chapel HIll


John Boyle

Senior Vice President

ICF International

Rockville, Md.


Bonnie Fisher


School of Criminal Justice

Research Fellow

Center for Justice Research

University of Cincinnati



Karen Heimer


Department of Sociology

University of Iowa

Iowa City


Linda Ledray

Founder and Director

SANE-SART Resource Service



Colin Loftin

Professor, and


Violence Research Group

School of Criminal Justice

University at Albany

State University of New York



Ruth D. Peterson

Emeritus Professor

Department of Sociology

Ohio State University



Nora Cate Schaeffer

Sewell Bascom Professor of Sociology

Department of Sociology

Center for Demography and Ecology

University of Wisconsin



Tom W. Smith

Survey Methodologist
National Opinion Research Center

University of Chicago



Bruce D. Spencer


Department of Statistics

Institute for Policy Research

Northwestern University

Evanston, Ill.





Carol C. House

Study Director