Download Background

Background
Measures of crime are important for many criminal justice research purposes. Researchers must decide on
offenses, units, and purpose before specifying measures of crime. Three broad questions loom in this
regard:
1.
2.
3.
What offenses should be measured?
What units of analysis should be used?
What is the research or policy purpose in measuring crime?
Approaches to measuring crime have at least one of three general purposes:
1.
2.
3.
monitoring
agency accountability
research
It is safe to say that the most widely used measures of crime are based on police records – “crimes known
to police.” Police-based measures are most widely used, but are subject to certain types of error.
Obviously, crimes not known to the police cannot be measured by consulting police records. Typically,
police measure crime through observation and reports by others. The FBI’s Uniform Crime Reports are
based on crimes reported to police, but there are additional sources of error: the UCR does not try to count
all crimes reported to police; individual states have varying definitions of crime; and, under the hierarchy
rule, if multiple crimes are committed in s single incident, only the most serious is counted. The UCR
system produces what is referred to as a summary-based measure of crime.
Some crime measures are incident-based. The most recent development in police-based measures at the
national level is the National Incident Based Reporting System (NIBRS), and efforts are ongoing to convert
the UCR to this system. NIBRS data hold the promise of being more reliable then conventional UCR data.
Victim surveys are alternative measures of crime, but are still subject to error, particularly in terms of
reliability problems, including recall difficulties like respondents not remembering some incidents and
“telescoping,” where respondents may not accurately recall an incident. The National Crime Victimization
Survey (NCVS) is attempting to respond to these problems through various strategies of redesign,
described in your text.
Delinquency, “victimless” crimes, and crimes rarely observed may be measured by self-report surveys.
Despite skepticism surrounding whether people will be truthful about crimes they have committed, selfreport surveys are probably the best method for trying to measure certain crimes that are poorly measured
by other techniques. Examples of this technique are the National Household Survey on Drug Abuse and
the “Monitoring the Future” high school survey, sponsored by the National Institute on Drug Abuse. There
are various validity and reliability issues surrounding self-report measures.
Surveillance systems have been developed to obtain alternative measures of drug use. One program is
Arrestee Drug Abuse Monitoring (ADAM), conducted by the National Institute of Justice (NIJ), which
provides an ongoing assessment of the prevalence of drug use among persons arrested for criminal
offenses. Even though ADAM is limited as a measure of drug use, it is an imaginative attempt to obtain a
different type of measure. Another surveillance measure is the Drug Abuse Warning Network, which
collects emergency medical treatment reports for “drug episodes” from samples of hospitals and medical
examiners nationwide. A completely different strategy is Pulse Check, sponsored by the Office of National
Drug Control Policy (ONDCP), which reports efforts by researchers to collect information from
ethnographers, local and federal law enforcement officers, and drug treatment service providers.
Sometimes, alternative measures of crime are collected for research or policy purposes. Indeed, none of the
regular series of crime measures meets the needs of those who are looking for specialized information
about crime. For example, victim surveys are more often being conducted in specific states, cities, or even
neighborhoods. In addition, incident-based data systems have become very sophisticated in some agencies,
targeting particular neighborhoods within cities. Yet another specialized technique involves independent
observations of crime.
Each measure of crime has strengths and weaknesses. Table 6-6 in the text provides an excellent summary
of the different measures of crime.