(including, but not limited to, the NCVS)—the methods used and the results obtained.

In pursuit of these goals, Chapters 2 through 6 of the report first consider definitions of rape and sexual assault and their legal histories and then detail several important sources of data on these victimizations.

In order to design a national survey on rape and sexual assault, consistent definitions for these criminal victimizations have to be defined. This task is complicated by the fact that these crimes are generally based on state, rather than federal, statutes. Chapter 2 explores rape and sexual assault in a legal context, analyzing the components of existing legal definitions and their differences and commonalities across jurisdictions. It also covers the historical context from which modern laws against rape and sexual assault have evolved and the changes in those statutes over time. The purpose of this chapter is to look for commonalities across jurisdictions that would be important to include in operational definitions.

The next four chapters detail the data that are available and the methods used to obtain them. Chapter 3 describes the statistical information about crimes available from law enforcement agencies. It looks at police incident reports and the FBI’s UCR. This system provides the official measure of crimes reported to the police, and it thus provides an important baseline for comparing other sources of survey-based data.

Addressing the estimation of victimization from population surveys, Chapter 4 provides a description of the NCVS. It includes a review of the survey’s history, methodology, and implementation, as well as the survey’s resulting estimates of rape and sexual assault. Chapter 5 looks at four other important surveys of rape and sexual assault that have been conducted over the past 25 years. They have used different methods and produced different results.

Chapter 6 compares and contrasts the data discussed in the previous three chapters, focusing on methods and results. It offers the panel’s conclusions that inform the central part of our charge to propose improvements to the design of BJS household surveys that measure rape and sexual assault.

In the second half (Chapters 7 through 10) of the report the panel turns to in-depth analyses of the NCVS and its adequacy for the goal of accurately measuring rape and sexual assault. It is important to note that the report does not provide the same in-depth evaluation of the other sources of data described in Chapter 5. Chapters 7, 8, and 9 focus on the NCVS as the current vehicle through which BJS measures victimization rates for rape and sexual assault. This focus on the NCVS reflects a prioritization of the panel’s time and resources: it does not imply that the panel believes that the other sources have better measures of rape and sexual assault or are subject to fewer errors.

Chapters 7 and 8 cover the error structure for the NCVS: sampling



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