THE PURPOSE OF EACH OF THE ILLINOIS SURVEYS, THE DIFFERENCES AMONG THEIR METHODOLOGIES, AND THE RAMIFICATIONS OF METHODOLOGICAL DETAILS FOR DATA ANALYSIS ARE DISCUSSED. BOTH CRIMES REPORTED TO THE POLICE AND UNREPORTED CRIMES WERE SURVEYED. APPROPRIATE USES OF VICTIMIZATION SURVEY DATA INCLUDE ADDING TO INFORMATION FROM THE FBI UNIFORM CRIME REPORTS ON THE STATUS OF CRIME AND COMPARING SURVEYS TO DETECT TRENDS, CRIME PATTERNS, OR THE INFLUENCE OF CRIME PREVENTION PROGRAMS. GENERAL WEAKNESSES OF VICTIMIZATION SURVEYS ARE THE TENDENCY OF VICTIMS TO AVOID REPORTING CRIMES PERPETRATED BY FAMILY MEMBERS OR FRIENDS, THE FAILURE OF SURVEYS TO MEASURE CRIME DISPLACEMENT, THE LACK OF SURVEY COMPARABILITY, AND THE EFFECT OF THE INTERVIEWER'S INTERPRETATION ON DATA INTEGRITY. PITFALLS COMMON TO THE USE OF VICTIMIZATION DATA ALSO ARE DISCUSSED, INCLUDING THOSE ASSOCIATED WITH CODING, WEIGHTING, DIFFERENCES IN TERMINOLOGY, AND THE USE OF SERIES DATA. THESE SURVEYS WERE USED AS THE BASIS FOR THE INVESTIGATION: (1) THE NATIONAL CRIME SURVEYS, CHICAGO, FOR 1972 AND 1974; (2) THE NATIONAL CRIME SURVEYS FOR ILLINOIS AS A WHOLE, 1974, 1975, AND 1976; (3) THE JOLIET AND PEORIA SURVEYS, CONDUCTED IN CONJUNCTION WITH THE URBAN HIGH CRIME REDUCTION PROGRAM FOR 1976; (4) THE REGION 20 (GREATER EGYPT) SURVEY OF THE GREATER EGYPT PLANNING COMMISSION FOR 1976; (5) THE CHAMPAIGN SURVEYS ALSO CONDUCTED AS PART OF THE URBAN HIGH CRIME REDUCTION PROGRAM IN 1977 AND 1978; AND (6) THE EVANSTON VICTIM SURVEY, CONDUCTED BY THE VICTIM-WITNESS ADVOCACY UNIT OF THE EVANSTON POLICE DEPARTMENT, 1977. TABULAR DATA, FOOTNOTES, AND A BIBLIOGRAPHY ARE INCLUDED AS WELL AS A LIST OF DATA SOURCES AND SAMPLES OF SURVEY QUESTIONNAIRES IN THE APPENDIXES. (AUTHOR ABSTRACT MODIFIED--PRG)