Theory n An explanation that systematically organizes the facts n Five criteria for a good theory u Consistent with the known facts u Logical, internally consistent u Parsimonious u Subject to empirical investigation u Able to predict

Empirical Research Methods n Case study n Survey n Written (group or mailed) n Interviews (face to face or telephone) n Observation n Records n Experiments n Longitudinal

Theory models n Elephant model n Proportion of variance model n St. Louis model

Proportion of Variance Model

St. Louis Model

Measuring crime n How much crime is there? n What are the patterns and trends n Who commits crime? n What is the nature of criminality? n Without such information u Explanations would not be possible u Rational policies would not be devised

Three ways to measure crime n Uniform Crime Reports (UCR) n Victimization surveys (NCS) n Self-report studies n Necessity of having more than one way of measuring crime

Uniform Crime Reports n Compiled by the FBI as received from over 16,000 police departments n Type I offenses (murder, rape, robbery, aggravated assault, burglary, larceny, motor vehicle theft, arson) n Type II offenses: all other offenses other than traffic violations n Characteristics of individuals arrested

UCR (continued) n Crimes cleared by arrest n Crime rates (number per 100,000 people, for comparison purposes) n Per cent change between last year and current year

Problems with the UCR n Many crimes are not reported (“Dark Figure” of crime) n Law enforcement practices, politics and PR n Methodological problems u Does not include federal crimes u Police department reporting varies u Element of subjectivity in deciding how to categorize acts

Problems with NCS n Overreporting due to misinterpretation of events n Underreporting (fear, embarrassment, forgetting) n With self-report, might lie

Crime patterns n More crime reported in warm weather n More murders and robberies in December n Higher rates in urban areas, especially violent crime n Highest rates in the West and the South n Lower in the Northeast, lowest in the Midwest

Crime patterns (continued) n Crime more common among the poor, according to UCR n Self-report indicates less class difference n Serious crime is more prevalent among lower SES, while less serious offenses are more evenly spread among all social classes