MAJOR PROBLEMS FACED BY CRIMINOLOGISTS IN CONDUCTING COMPARATIVE RESEARCH ARE THE VALIDITY AND THE COMPARABILITY OF INTERNATIONAL CRIMINAL STATISTICS. IN ATTEMPTING TO COMPARE CRIMINAL STATISTICS FOR GIVEN CRIMINAL ACTS, TWO FUNDAMENTAL METHODOLOGICAL CONSIDERAIONS MUST BE TAKEN INTO ACCOUNT: (1) THE IDENTIFICATION OF POSSIBLE DISCREPANCIES BETWEEN THE NOMINAL AND THE OPERATIONAL DEFINITION OF CRIMINAL ACTS WITHIN CULTURES OR SOCIETIES, AND (2) THE IDENTIFICATION OF POSSIBLE DISCREPANCIES BETWEEN VARIOUS NOMINAL DEFINITIONS WHEN COMPARED ACROSS CULTURES OR SOCIETIES. WITH REGARD TO THE VALIDITY OF CRIMINAL STATISTICS, OVERT CRIMINAL BEHAVIOR COMMITTED IN A GIVEN TIME AND SPACE MUST CORRESPOND TO LEGAL CODES AND THE JUDICIAL AND SENTENCING PROCESS AND CONSIDERATION MUST BE GIVEN TO THE EXTENT TO WHICH CRIME STATISTICS REPORTED BY THE POLICE REPRESENT THE TRUE MAGNITUDE OF CRIME IN A PARTICULAR COUNTRY. SOURCES OF INTERNATIONAL CRIME STATISTICS ARE IDENTIFIED AND EVALUATED. AN INDEX OF CRIME AND OFFICIAL CRIMINAL STATISTICS IS PRESENTED, AND STATISTICAL MODELS ARE APPLIED TO ASCERTAIN THE RELIABILITY OF HOMICIDE RATES. THE IMPACT OF COMPARATIVE CRIMINOLOGICAL RESEARCH ON THE DEVELOPMENT AND ASSESSMENT OF CRIMINOLOGICAL THEORIES IS DISCUSSED. A GENERAL STATISTICAL MODEL IS APPENDED. REFERENCES ARE CITED. (DEP)