OFFICIAL STATISTICS INCLUDE BOTH OFFENDER-BASED DATA (CHARACTERISTICS OF OFFENDERS BASED ON ANALYSIS OF ARREST, COURT, AND PRISON RECORDS) AND OFFENSE-BASED DATA (ENUMERATIONS OF CRIMES KNOWN TO THE POLICE). PROBLEMS IN USING OFFICIAL STATISTICS, SUCH AS THOSE COMPILED IN THE UNIFORM CRIME REPORTS, TO ESTIMATE THE EXTENT OF CRIME HAVE TO DO WITH THE PUBLIC'S UNDERREPORTING OF CERTAIN CRIMES AND WITH INCONSISTENCIES IN POLICE REPORTING PRACTICES. SELF-REPORTED DATA ON DEVIANT ACTIVITY GENERALLY HAVE BEEN LIMITED TO STUDIES OF JUVENILE DELINQUENCY. ALTHOUGH SAMPLE BIAS AND OTHER METHODOLOGICAL PROBLEMS HAVE BEEN ENCOUNTERED, IT APPEARS THAT SELF-REPORTED DATA CAN BE USEFUL IN ESTIMATING THE NATURE AND EXTENT OF DEVIANT BEHAVIOR IN SPECIFIC GROUPS OF INDIVIDUALS. VICTIM SURVEY RESEARCH HAS SHOWN THAT VICTIM SURVEYS NOT ONLY PROVIDE MORE COMPLETE INFORMATION ON THE EXTENT OF CRIME THAN CAN BE DERIVED FROM OFFICIAL STATISTICS, BUT ALSO OFFER SIGNIFICANT DATA ON THE CHARACTERISTICS OF VICTIMS AND OFFENDERS, VICTIM-OFFENDER RELATIONSHIPS, THE CIRCUMSTANCES UNDER WHICH OFFENSES OCCUR, AND CITIZEN ATTITUDES AND PERCEPTIONS RELATIVE TO CRIME-RELATED MATTERS. VICTIMIZATION STUDIES CONSISTENTLY HAVE POINTED TO THE EXISTENCE OF UNREPORTED CRIME, BUT LITTLE HAS BEEN DONE TO TEST THE RELIABILITY OF VICTIMIZATION DATA IN ESTIMATING THE ACTUAL INCIDENCE OF CRIME. IT IS CONCEIVABLE THAT RELIABLE ESTIMATES OF THE NATURE AND EXTENT OF CRIME IN A GIVEN COMMUNITY COULD BE OBTAINED BY COMBINING VICTIMIZATION DATA AND OFFICIAL STATISTICS. A STUDY UNDERTAKEN IN PUEBLO, COLO., DEMONSTRATED HOW OFFICIAL STATISTICS CAN BE USED TO VERIFY ESTIMATES OF THE EXTENT OF REPORTED AND UNREPORTED CRIME DERIVED FROM VICTIMIZATION SURVEY DATA. HOWEVER, BECAUSE VICTIMIZATION SURVEYS ARE EXPENSIVE, IT IS LIKELY THAT OFFICIAL REPORTS WILL CONTINUE TO BE THE MAJOR SOURCE OF DATA FOR CRIME ESTIMATES. (LKM)