The NCS measures selected crimes, including offenses not reported to the police, by means of a large-scale and continuous household survey. Demographic and socioeconomic variables are used for gauging the degree to which persons across the Nation experienced criminal victimization during 1981. Data also are provided on certain characteristics of violent offenders, on the basic circumstances and outcomes of criminal incidents, and on patterns of reporting to the police. Interviews at 6-month intervals with the residents of a representative sample of about 59,000 housing units (126,000 persons age 12 and over) formed the basis for examining the following personal or household crimes: rape, robbery, assault, purse snatching, pocket picking, noncontact personal larceny, residential burglary, household larceny, and motor vehicle theft. Selected findings from 106 data tables are presented, together with charts and explanatory information. A survey methodology is appended to aid in the interpretation of survey results.